A massive suicide truck bombing rocked a highly secure diplomatic area of Kabul on Wednesday morning, killing 80 people and wounding as many as 350, an attack that left a scene of mayhem and destruction and sent a huge plume of smoke over the Afghan capital.

The target of the explosion in the Wazir Akbar Khan area was not immediately known, but Ismail Kawasi, spokesman of the public health ministry, said most of the casualties were civilians, including women and children.

It was one of the worst attacks Kabul had seen since the drawdown of foreign forces from the country at the end of 2014. The bombing also raised serious questions about the Afghan government’s ability to secure the war-battered nation.

Images from the scene showed the German Embassy and several other embassies located in the area heavily damaged. Germany, Japan and Pakistan said some of their embassy employees and staff were hurt in the explosion.

The BBC said a driver for the British broadcaster was killed and four of its journalists were wounded. Afghanistan’s private TOLO Television also reported a staffer killed; Germany said an Afghan security guard outside its embassy was among those killed.

The explosion took place at the peak of Kabul’s rush hour, when roads are packed with worktime commuters. Najib Danish, deputy spokesman for the Interior Ministry, said the bomber detonated his truck filled with explosives close to a busy intersection in the Wazir Akbar Khan district. The blast left a gaping crater, at least five yards deep.

The neighborhood is considered Kabul’s safest area, with foreign embassies protected by dozens of 10-foot-high blast walls and government offices, guarded by police and national security forces. The German Embassy, the Foreign Ministry and the Presidential Palace are all in the area, as are the British and the Canadian embassies. The Chinese, Turkish and Iranian embassies are also located there.

The U.S Embassy and the NATO mission in Kabul are also near, about a kilometer (half mile) away from the site. Both condemned the attack and the alliance praised “the courage of Afghan Security Forces, especially the police and first responders.”

Local TV footage showed shocked residents soaked in blood stumbling about, then being ferried away to hospitals. Passers-by stopped and helped the wounded into private cars, others congregated outside the nearby Italian-run Emergency Hospital.

No group immediately claimed responsibility for the blast, though both the Taliban and the Islamic State group (I.S.) have staged large-scale attacks in the Afghan capital in the past.

The Taliban later Wednesday issued a statement denying any involvement and condemning all attacks against civilians. Zabihullah Mujahid, spokesman for the Taliban, said the Kabul explosion had “nothing to do with the Mujahedeen of Islamic Emirate,” as the Taliban call themselves. Even though the Taliban claim they are only waging war against the Kabul government and foreign forces in Afghanistan, most of the casualties of their attacks have been civilians.

A statement from the Ministry of Interior Affairs said it condemned “in the strongest terms the terrorist attack” that killed so many, including women and children. “These heinous acts go against the values of humanity as well values of peaceful Afghans,” it added.

Afghan President Ashraf Ghani also condemned the attack, which came just days into the Muslim holy month of Ramadan. A statement from his office quoted Ghani as saying that “the terrorists, even in the holy month of Ramadan, the month of goodness, blessing and prayer, are not stopping the killing of our innocent people.”

Germany’s Foreign Minister Sigmar Gabriel said that along with the Afghan guard who was killed, a German diplomat was lightly wounded while an Afghan staffer sustained severe injuries. Gabriel offered his condolences to the guard’s family.

Neighboring Pakistan denounced the “terrorist attack in Kabul” and its Ministry of Foreign Affairs said the bombing “caused damage to the residences of some Pakistani diplomats and staff, living in the close vicinity, and inflicted minor injuries to some.”

China’s foreign ministry said its embassy was partly damaged but that no staffers or Chinese citizens were injured.

Germany has had troops in Afghanistan for 15 years, primarily concentrated in the north in and around Mazar-e-Sharif. They’re currently one of the biggest contributors to the NATO-led Resolute Support mission with around 980 soldiers on the ground to support and train Afghan security forces.

Wednesday’s explosion was so heavy that more than 50 vehicles were either destroyed or damaged around the site of the attack. “We don’t know at this moment what was the target,” said Danish.

Residents described a mushroom cloud over Kabul and windows were shattered in shops, restaurants and other buildings up to a kilometer from the blast site.

“There are a large number of casualties, but I don’t know how many people are killed or wounded,” said an eyewitness, Gul Rahim.

Mohammad Haroon, who owns a sporting goods store near the site, said all the windows on his shop and others around him were shattered. “I’ve never seen such a powerful explosion in my life,” he said.

“Business will be very bad, nobody will come for shopping anymore,” he added.

Kawasi, the health official, said the wounded were admitted to different Kabul hospitals.

Shortly after the explosion, all roads in Wazir Akbar Khan were blocked off by Afghan security forces and helicopters were deployed over the neighborhood.

Last month, the Afghan Taliban announced the beginning of their spring offensive, promising to build their political base in the country while focusing military assaults on the international coalition and Afghan security forces.

U.S. and Afghan forces have been battling the Taliban insurgency for more than 15 years. The United States now has more than 8,000 troops in Afghanistan, training local forces and conducting counterterrorism operations. In the past year, they have largely concentrated on thwarting a surge of attacks by the Taliban, who have captured key districts, such as Helmand province, which U.S. and British troops had fought bitterly to return to the government.

Yet the Afghan war shows no signs of letting up and the emergence of the local I.S. branch has made Afghanistan even more volatile.

The affiliate, known as the Islamic State in Khorasan, an ancient name for parts of Afghanistan, Iran and Central Asia, has taken credit for several brazen assaults on Kabul, including the attack on a military hospital on March 8 when I.S. gunmen, wearing white lab coats, stormed a military hospital in Kabul, killing 50 people.