KABUL, Afghanistan (AP) — Afghans on Thursday mourned the loss of family members, friends and colleagues a day after a massive truck bomb in the capital left at least 90 people dead and more than 450 others wounded in one of the worst extremist attacks since the drawdown of foreign forces from Afghanistan in 2014.

Scores of people waited in hospitals to learn the status of family members and friends wounded in Wednesday's attack.

The bomber drove into Kabul's heavily guarded diplomatic quarter during the morning rush, leaving behind chaos and destruction. Most of the casualties were civilians, including women and children, but the dead also included Afghan security guards.

There was no claim of responsibility.

The explosives were hidden in a tanker truck used to clean out septic systems, according to Najib Danish, deputy spokesman for the interior minister. The trucks are common in Kabul, a city of nearly four million people with no sewage system that mostly depends on septic tanks, and where open sewers are common.

The blast gouged a crater about 5 meters (15 feet) deep near Zanbaq Square in the Wazir Akbar Khan district, where foreign embassies are protected by their own security personnel as well as Afghan police and National Security Forces. The nearby German Embassy was heavily damaged.

Also in the area is Afghanistan's Foreign Ministry, the Presidential Palace and its intelligence and security headquarters, guarded by soldiers trained by the U.S. and its coalition partners.

Afghanistan's war, the longest ever involving U.S. troops, has shown no sign of letting up and the introduction into the battle of an Islamic State affiliate has made the country only more volatile.

Although they are small in number, militants from the Islamic State in Khorasan — an ancient name for parts of Afghanistan, Iran and Central Asia — have taken credit for several brazen assaults on the capital.