(CNN) Yemeni officials said Saudi airstrikes targeting a military base on Tuesday hit a nearby school, injuring at least a half dozen students.

The information came from two officials with the governor's office in Ibb province, where the school is located, as well as Houthi sources from the rebel group that is fighting for control of the country.

A third source, with the Education Ministry in Ibb, said three students had been killed at the Al Bastain School in Maitam, in southwestern Yemen, as a result of an airstrike.

The officials from Ibb's governor's office said the Al Hamza military base was targeted because Houthis have been sending reinforcements from Ibb to nearby provinces. There were no casualties on the base, the officials said, but it was heavily damaged.

The school, which is about 500 meters (one-third of a mile) from the base, was not the main target, the officials said. Schoolchildren were heading to their lunch break when the attacks took place, the officials said.

The incident was another example of what has become evident in recent days: The chaos in Yemen, now the scene of some of the most chaotic fighting in the Middle East, has left civilians -- noncombatants, both locals and foreigners -- caught in the crossfire.

Those trying to escape the violence, either by leaving their homes or by leaving the country altogether, have been flung into a vortex of fear, fatigue, flight and death.

Explosions shattered windows in Sanaa, the country's capital. The fighting has killed hundreds of people in less than two weeks.

At least 74 children are known to have been killed and 44 children maimed since the fighting began on March 26, UNICEF said Monday in a statement. That did not include the children reportedly killed Tuesday in Maitam.

Separately, Saudi airstrikes wiped out about a fifth of the armored vehicles recently captured by southern separatists opposing the Houthis near Aden, according to a senior official in the separatist movement.

The official expressed frustration about the lack of coordination between the Saudi military and friendly forces in the region, including the anti-Houthi southern separatists. (The Houthis are also sometimes referred to as southern separatists).

"The Saudis have no one on the ground in Aden," he said, calling for the military to work out a means of coordination. "There is very little coordination."

The group had recently captured about 100 pieces of mixed armor. Among the captured weaponry, the official said, were tanks, armored personnel carriers, and some large artillery. About 20 pieces were destroyed in the Saudi attack that took place near an old oil refinery.

16 million without electricity

Over the weekend, a Saudi-led coalition smashed parts of Yemen's Defense Ministry Central Command in the capital, senior Yemeni officials said.

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Despite the rain of bombs, the Houthis still control Sanaa. But the airstrikes have destroyed much of the city's infrastructure.

The electricity has gone out on 16 million Yemenis living in Houthi-held areas, the Yemeni officials said. Many fear they will lose access to clean water as well.

Yemenis and foreigners are scrambling to leave. Passengers carrying duffel bags and plastic sacks stuffed with clothes were seen boarding an Air India flight as they hastened to leave the capital. Some of them sprinted to the plane.

This was a flight that no one wanted to miss.

Many were not newcomers to Yemen. Damodar Thakur, a professor at Sanaa University, had lived in the capital for 34 years.

"I never felt like a foreigner," he said.

He was exhausted by the shelling.

"At night, my goodness!" he said. "Gunshots being fired every minute. Sometimes the sky full of sparkling lights. Some women crying, children terrified. Really bad."

Over the last few days, India has evacuated 2,500 people from Yemen, said Vijay Kumar Singh, the Indian deputy foreign minister overseeing the evacuation. The flights are going to Djibouti, a small African nation about 430 kilometers (265 miles) away.

Some evacuees are fleeing on boats from port cities such as Aden.

"More cars in the streets in #Aden. Scared families rushing away in cars with smashed windows & suitcases & mattresses on the roof," tweeted Robert Mardini , head of operations for the Middle East for the International Committee of the Red Cross.

One plane, one four-hour window

Houthi rebels control Sanaa, including the airport. But because of the airstrike campaign , the Saudis to some extent control air access, so getting people out requires coordination. The Saudi air force gave Air India a four-hour window to go to and from Sanaa and a specific travel route for a safe landing.

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As the Air India plane approached the city, the crew could see the scars of the fighting. There were no cars on the roads. Dozens of buildings were destroyed.

At the airport, the landing strips and airport terminal were untouched by Saudi bombs, but buildings on the outskirts of the airport and planes along the airstrip had been blown to bits.

Loading of the passengers was swift. They approached the planes carrying boarding passes -- a touch of normalcy in an otherwise abnormal event. They didn't pay for the flight, but they had to purchase exit visas from the Houthis.

Children sat on their parents' laps to maximize the number of people on the plane. Some passengers fell asleep as soon as they took their seats before takeoff. Everyone seemed to carry the weight of war, especially nurses who had tended the wounded.

From Djibouti, the evacuees will most likely disperse to their home nations.

"Now I can only pray for Yemen and those we left behind," Thakur said.

Descent into chaos

Yemen has descended into chaos in the weeks since Houthi rebels, Shiites who complain of being marginalized in the majority Sunni country, forced President Abdu Rabu Mansour Hadi from power.

The Houthis put Hadi under house arrest when they overran Sanaa in January. But Hadi escaped in February, fled to Aden and declared himself still President.

Houthis and their allies, including those loyal to Hadi's predecessor, then fought Hadi's forces in the Aden area. Hadi fled Aden in late March, ultimately for Saudi Arabia, when the rebels and their military allies advanced on the city.

The conflict prompted Saudi Arabia, a predominantly Sunni nation and Yemen's neighbor to the north, to intervene with force along with other Arab nations.

The Houthis are allied with Iran, Saudi Arabia's bitter rival across the Persian Gulf, and the Saudis do not want an Iranian proxy in power on their border.

At his daily briefing on Tuesday, Saudi Brig. Gen. Ahmed Asiri told reporters that the ties between the rebels and Iran were clear.

He accused Iran of training Yemeni youths to use military aircraft and weapons. After the Houthis seized Sanaa, he said, "there were 14 flights a week coming from Iran carrying weapons and ammunition for the Houthi militia."

Photos: Unrest in Yemen The sky over Sanaa, Yemen, is illuminated by anti-aircraft fire during a Saudi-led airstrike on Friday, April 17. The coalition's warplanes have been carrying out strikes against Houthi rebels since President Abdu Rabu Mansour Hadi fled the country in late March. Hide Caption 1 of 42 Photos: Unrest in Yemen A Yemeni boy holds a rifle as Houthi supporters attend a rally in Sanaa, Yemen, on Sunday, April 5, protesting airstrikes carried out by a Saudi-led coalition against Houthi rebels. Hide Caption 2 of 42 Photos: Unrest in Yemen Yemenis dig graves on Saturday, April 4, to bury the victims of a reported airstrike by the Saudi-led coalition in the village of Bani Matar, Yemen. Hide Caption 3 of 42 Photos: Unrest in Yemen Yemenis search for survivors in the rubble of houses destroyed by Saudi-led airstrikes on April 4 in a village near Sanaa. Hide Caption 4 of 42 Photos: Unrest in Yemen Central Sanaa is covered in dust on Friday, April 3. Airstrikes have turned the bustling capital of Yemen into a ghost town. Hide Caption 5 of 42 Photos: Unrest in Yemen A Yemeni man loads a TV set into a van as he prepares to flee Sanaa on Thursday, April 2. Hide Caption 6 of 42 Photos: Unrest in Yemen Militiamen loyal to Hadi take positions on a street in Aden, Yemen, on Thursday, April 2. Houthi rebels seized the presidential palace in Aden, a neutral security official and two Houthi commanders in Aden told CNN. The Houthis are Shiite Muslims who have long felt marginalized in the majority Sunni country. The Sunni Saudis consider the Houthis proxies for the Shiite government of Iran and fear another Shiite-dominated state in the region. Hide Caption 7 of 42 Photos: Unrest in Yemen A framed photo and a purse hang on the wall of a house destroyed by an airstrike near the Sanaa airport on Tuesday, March 31. Hide Caption 8 of 42 Photos: Unrest in Yemen Buildings burn at the Jabal al-Hadid military camp in Aden on Saturday, March 28. Yemeni military officials said an explosion rocked the camp that houses a weapons depot, killing and wounding several people. The camp reportedly had been taken by security forces loyal to former Yemeni President Ali Abdullah Saleh. Some of the forces aligned with the Houthis are also loyal to Saleh, who resigned in 2012 after months of Arab Spring protests. Hide Caption 9 of 42 Photos: Unrest in Yemen Yemeni supporters of the Houthi movement attend a demonstration against Saudi military operations Thursday, March 26, in Sanaa. Hide Caption 10 of 42 Photos: Unrest in Yemen People search for survivors under the rubble of houses destroyed by airstrikes near the Sanaa Airport on March 26. Hide Caption 11 of 42 Photos: Unrest in Yemen Members of Yemen's General People's Committee deploy in Aden, Yemen, on Wednesday, March 25. The militiamen are loyal to Hadi. Hide Caption 12 of 42 Photos: Unrest in Yemen On March 25, honor guards in Sanaa carry the coffins of victims who were killed in suicide bombing attacks several days earlier. Deadly explosions in Sanaa rocked two mosques serving the Zaidi sect of Shiite Islam, which is followed by the Houthi rebels that took over the capital city in January. Hide Caption 13 of 42 Photos: Unrest in Yemen Yemenis stand in front of burning tires during an anti-Houthi protest in Taiz, Yemen, on Tuesday, March 24. Hide Caption 14 of 42 Photos: Unrest in Yemen Medics treat an anti-Houthi protester who was injured during clashes with pro-Houthi police in Taiz on March 24. Hide Caption 15 of 42 Photos: Unrest in Yemen Armed men inspect damage after an explosion at the Al Badr mosque in Sanaa on Friday, March 20. Hide Caption 16 of 42 Photos: Unrest in Yemen A man in Aden holds a police shield that he looted from a base belonging to forces loyal to Saleh on Thursday, March 19. Hide Caption 17 of 42 Photos: Unrest in Yemen Houthi supporters in Sanaa deploy giant national flags Wednesday, March 18, during a demonstration to mark the fourth anniversary of the "Friday of Dignity" attack. In 2011, forces loyal to Saleh opened fire on protesters who had gathered in Sanaa to demand the ouster of Saleh and his regime. Hide Caption 18 of 42 Photos: Unrest in Yemen Supporters of Ahmed Ali Abdullah Saleh, the son of the former President, wave banners and shout slogans during a demonstration in Sanaa on Tuesday, March 10. The demonstrators were demanding presidential elections be held and that the younger Saleh run for office. Hide Caption 19 of 42 Photos: Unrest in Yemen A child raises his fist during a rally by Houthi supporters in Sanaa on Friday, March 6. Hide Caption 20 of 42 Photos: Unrest in Yemen Thousands of armed Yemeni tribal members gather in the southern province of Shabwa on Monday, February 23. Hide Caption 21 of 42 Photos: Unrest in Yemen Supporters of the separatist Southern Movement perform prayers during a demonstration in Aden on Friday, February 13. Hide Caption 22 of 42 Photos: Unrest in Yemen Houthi fighters guard the gate of the presidential palace where a bomb went off and wounded three people in Sanaa on Saturday, February 7. Hide Caption 23 of 42 Photos: Unrest in Yemen Yemeni soldiers guard the presidential palace in Sanaa on Friday, February 6. Hide Caption 24 of 42 Photos: Unrest in Yemen Members of the Houthi movement and their allies attend a meeting in the Yemeni capital on Sunday, February 1. Hide Caption 25 of 42 Photos: Unrest in Yemen Supporters of the separatist Southern Movement flash the victory sign after they seized police security checkpoints on Saturday, January 24, in Ataq, the capital of the Shabwa province in Yemen. Policemen were told to give up their weapons and return to their bases before the militiamen raised flags of the formerly independent South Yemen at the checkpoints. Hide Caption 26 of 42 Photos: Unrest in Yemen Houthi rebels fight with Yemeni protesters during a rally in Sanaa on January 24. Thousands of Yemenis took to the streets of Sanaa in the largest demonstration against Houthis since the Shiite militiamen overran the capital in September. Hide Caption 27 of 42 Photos: Unrest in Yemen On Friday, January 23, Houthis carry coffins of those killed during recent clashes with presidential guard forces in Sanaa. Hide Caption 28 of 42 Photos: Unrest in Yemen A Houthi militiaman sits near a tank near the presidential palace in Sanaa on Thursday, January 22. Hide Caption 29 of 42 Photos: Unrest in Yemen Houthi men wearing army uniforms stand guard on a street leading to the presidential palace in Sanaa on Wednesday, January 21. Hide Caption 30 of 42 Photos: Unrest in Yemen A wounded man rests at a hospital in Sanaa on January 21. He was reportedly injured in fierce clashes the previous day. Hide Caption 31 of 42 Photos: Unrest in Yemen A tank is stationed in front of the Sanaa house of President Abdu Rabu Mansour Hadi on January 21. Hide Caption 32 of 42 Photos: Unrest in Yemen A Houthi rebel mans a checkpoint near the presidential palace on January 21. Hide Caption 33 of 42 Photos: Unrest in Yemen A man walks inside a heavily damaged house near the presidential palace on Tuesday, January 20. Hide Caption 34 of 42 Photos: Unrest in Yemen A woman walks past closed shops in Sanaa on January 20. Hide Caption 35 of 42 Photos: Unrest in Yemen An armed member of the Houthi movement stands guard in the streets of Sanaa on January 20. Hide Caption 36 of 42 Photos: Unrest in Yemen A man surveys his damaged home in Sanaa on January 20. Hide Caption 37 of 42 Photos: Unrest in Yemen Houthis inspect a damaged mosque in Sanaa on January 20. Hide Caption 38 of 42 Photos: Unrest in Yemen Houthi men raise their weapons during clashes near the presidential palace on Monday, January 19. Hide Caption 39 of 42 Photos: Unrest in Yemen Smoke and flames rise in Sanaa during heavy clashes between presidential guards and Houthi rebels on January 19. Hide Caption 40 of 42 Photos: Unrest in Yemen Tribal soldiers protecting the city from Houthi rebels stand guard at the city borders in Marib, Yemen, on January 19. Hide Caption 41 of 42 Photos: Unrest in Yemen Houthi men guard a Sanaa street on January 19. Hide Caption 42 of 42

What role is U.S. playing?

The U.S. role in backing the Saudis has grown since the bombing campaign began two weeks ago.

"We have expedited weapons deliveries, we have increased our intelligence sharing, and we have established a joint coordination planning cell in the Saudi operation center," Deputy Secretary of State Anthony Blinken said. In addition, the United States has promised to resupply the Saudi weapons stocks used in the last two weeks.

U.S. Defense Secretary Ash Carter "emphasized the importance of limiting civilian casualties when conducting airstrikes" when he spoke with Saudi Defense Minister Prince Mohammed bin Salman on Monday, the Pentagon said.

What about sharing intelligence when it comes to identifying targets?

That's a sensitive issue, given the rebels' ties to Iran and concerns about civilian casualties.

Guidance from U.S. Central Command stops short of allowing the United States to tell the Saudis what targets to bomb, according to two U.S. defense officials who confirmed details of the guidance to CNN, but declined to be identified due to the sensitivity of the matter.

The guidance allows the United States to review targets the Saudis have selected, the officials said, and advise them if there are civilian areas nearby or other "no go" spots such as mosques and hospitals.