Story highlights Opposition fighters attack an air force intelligence building, a Free Syrian Army official says

The Free Syrian Army pulls all but a few fighters from Rastan, he adds

Marie Colvin's remains should arrive in the U.S. on Tuesday, her brother says

62 people are killed across Syria on Sunday, an opposition group says

Opposition fighters attacked a Syrian air force intelligence building outside Damascus on Sunday and tried to fend off an intense assault on the town of Rastan, said a leader in the Free Syrian Army.

Three people died and dozens more -- most of them children -- were hurt as government forces hit Rastan with 15 rockets in as many minutes Sunday, opposition activists said. Graphic video posted on YouTube shows three girls, one of them a 1-year-old, suffering from severe injuries purportedly sustained in that attack.

By early Monday morning, opposition forces claimed to have driven out the army while at the same ceding that most of their own fighters had "retreated for ... tactical reasons," said Malek Al Kurdi, deputy head of the Free Syrian Army.

He added that his armed opposition group, made up largely of Syrian military defectors, now only has a small unit inside Rastan, which is between the Middle Eastern country's third and fourth largest cities, respectively, of Homs and Hama.

A team of Free Syrian Army fighters used machine guns Sunday night to attack the air force intelligence building in Harasta, which is near Damascus, according to Al Kurdi.

The opposition Local Coordination Committees of Syria said 18 people were killed Sunday in Hama and 17 in Homs, out of at least 62 slain nationwide.

Homs, especially, has been a hotbed of violence and devastation for weeks. Opposition activists fear the nightmare there will only get worse after government forces stormed the embattled neighborhood of Baba Amr, where six people were reportedly executed Sunday.

The neighborhood, which is five square miles (eight square kilometers), had endured nearly a month of shelling before rebel forces announced a "tactical retreat" Thursday.

Osamah, a Syrian-based media director for the group who didn't want to use his last name for safety reasons, reported arrests, rape and torture in Baba Amr by President Bashar al-Assad's forces.

The International Committee of the Red Cross has repeatedly been denied entry to Baba Amr, even after seemingly getting permission from Syrian authorities at one point.

JUST WATCHED Red Cross denied access in Syria Replay More Videos ... MUST WATCH Red Cross denied access in Syria 03:07

On Sunday, aid workers from the ICRC and Syrian Red Crescent did begin distributing food and supplies in Abel, a village three kilometers from Homs, an ICRC spokeswoman said.

"The plan is to continue to the Inshaat and al-Tawzee neighborhoods, both in Homs, to the displaced families and people who fled Baba Amr," Carla Haddad Mardini said. "We hope to enter Baba Amr today, but nothing is confirmed."

New videos that have surfaced from Homs suggest a fresh wave of killings by the Syrian military after the fall of Baba Amr.

JUST WATCHED Activist: Assad will have to kill us all Replay More Videos ... MUST WATCH Activist: Assad will have to kill us all 02:07

Opposition activists provided CNN with the videos, purportedly showing 17 civilians' bodies that were discovered Wednesday in villages near Baba Amr after a government assault.

JUST WATCHED Homs resident: 'Trying to stay alive' Replay More Videos ... MUST WATCH Homs resident: 'Trying to stay alive' 01:42

Much of the footage is too graphic to broadcast, but an analysis of the videos showed at least 12 bodies.

JUST WATCHED CNN spends '72 Hours in Hell' in Syria Replay More Videos ... MUST WATCH CNN spends '72 Hours in Hell' in Syria 00:10

In one video, the mother of victim Mahmoud al-Zoubi reacts to seeing her son's body for the first time since his death, said the activist who provided the footage.

JUST WATCHED The way forward in Syria debated Replay More Videos ... MUST WATCH The way forward in Syria debated 05:46

"Bring an end to Bashar!" she wails before falling to the ground, shaking, as others try to console her.

The violence in Homs has also claimed the lives of several journalists, including reporter Marie Colvin and photographer Remi Ochlik, who both died February 22.

William Colvin said the remains of his sister, Marie, are in Paris and the family expects the editor of the Sunday Times to bring them to the United States on a New York-bound flight Tuesday. Her and Ochlik's bodies arrived in Paris from Damascus on Sunday, the French foreign ministry said.

Al Kurdi, from the Free Syrian Army, further alleged government forces landed Saturday night in the rugged mountains of Jabal Al-Akhdar "in order to conduct random arrests of civilians."

Since unrest began about a year ago, Syria's government has routinely blamed violence in the country on "armed terrorist groups" and portrayed its forces as trying to protect the public interest and security.

State-run news agency SANA said 16 "army and law enforcement martyrs" killed by such groups were buried Sunday.

Also, the news agency reported that a bomb planted by a "terrorist group" killed a child and injured five others in the same family.

CNN cannot independently confirm reports across Syria because the government has severely restricted the access of international journalists.

The international debate over the situation in Syria continued to rage, most pointedly in Lebanon where groups for and against President Bashir al-Assad's regime staged dueling protests.

At the opposition rally, pop singer Fadel Shakir sang, "For the great people of Syria, our brothers and sisters in Homs, your new dawn will come and freedom will come, the tyranny will end."

The crowd chanted, "The people want the execution of the butcher" and "Freedom, freedom, no matter what."

"All of our brothers and people in the Arab and Muslim world, our people are being slaughtered, our mosques are being demolished. What will you do? When will you mobilize your people for their rescue?" said Salafi Sheikh Ahmed Al-Asir, who organized the rally.

Demonstrators elsewhere waved Syrian flags and held pictures of al-Assad, to show their support for the government.

Meanwhile, Israel -- which has fought Syria in four wars since Israel's statehood in 1948 -- offered humanitarian assistance to the nation's citizens Sunday.

"The state of the Jewish nation cannot sit still while horrors are taking place and people are losing their world in a neighboring country. It is our moral duty to provide aid and awake the world to stop the manslaughter," Foreign Minister Avigdor Liberman said.

Israeli President Shimon Peres had a message for the Syrian people Sunday as well.

"The Middle East is undergoing its greatest storm in history, with horrible bloodshed in Syria, where a tyrant is killing his people, killing his children. I admire the courage of the Syrian people. And I wish them peace and freedom from the depths of all of our hearts," Peres said at a speech in Washington to the pro-Israel lobby the American Israel Public Affairs Committee (AIPAC).

The United Nations estimates more than 7,500 people have died since the beginning of the Syrian conflict almost a year ago, while the LCC says more than 9,000 people have been killed. The Syrian government says more than 2,000 security personnel have been killed in the violence.

Despite incessant fears of the government onslaught, protesters took to the streets of Hama on Sunday to make sure their voices were heard.

"May God humiliate you, Bashar," they chanted. "May God protect the Free Syrian Army."