Update 2.34pm: A suicide bomber driving an ambulance has killed at least 95 people and wounded 151 more in an attack claimed by the Taliban in the Afghan capital Kabul, authorities said.
The bombing on Saturday came just a week after Taliban militants killed 22 at an international hotel in the city.
The attacker used the ambulance to get through a security checkpoint in central Kabul, telling police he was taking a patient to a nearby hospital, said Nasrat Rahimi, deputy spokesperson for the Interior Ministry.
He then detonated his explosives at a second checkpoint.
The Health Ministry said 95 were killed and 151 wounded.
"The majority of the dead in the attack are civilians, but of course we have military casualties as well," Mr Rahimi said.
He said four suspects had been arrested and were being questioned but he didn't elaborate.
Zabihullah Mujahid, a Taliban spokesman, claimed responsibility for the bombing, which sent thick, black smoke into the sky from the site near the government's former Interior Ministry building.
Also nearby are the European Union and Indian consulates.
The powerful explosion was felt throughout the capital and covered the blast area in smoke and dust.
At the scene, dozens of vehicles were damaged or destroyed. Several shops, including some selling antiques and photography equipment, were also destroyed.
Windows at nearby Jamhuriat government hospital were shattered and its walls damaged. People ran out to help and ambulances arrived to transport dozens of wounded to area hospitals.
The International Committee of the Red Cross condemned the attack in a tweet, saying: "The use of an ambulance in today's attack in #Kabul is harrowing. This could amount to perfidy under IHL. Unacceptable and unjustifiable."
It was the second successful Taliban attack in a week on high security targets in the city.
Last Saturday, six Taliban militants attacked the Intercontinental Hotel, leaving 22 people dead, including 14 foreigners.
Some 150 guests fled the gun battle and fire sparked by the assault by climbing down bedsheets from the upper floors.
The US State Department said multiple American citizens were killed and injured in the attack.
Afghan security forces have struggled to fight the Taliban since the US and Nato formally ended their combat mission in 2014.
Earlier: Taliban claims car bombing in Kabul that left at least 40 dead
The Afghan Public Health Ministry says 40 people have been killed and 140 wounded in a suicide car bombing in the capital Kabul, claimed by the Taliban.
Nasrat Rahimi, deputy spokesperson for the Interior Ministry, said the attacker used an ambulance to get through one security checkpoint by telling police he was taking a patient to a nearby hospital.
He detonated his explosives at a second check point, Rahimi said.
Zabihullah Mujahid, a Taliban spokesman, claimed responsibility for the attack, which sent thick, dark smoke into the sky from from the site of the explosion near the government's former Interior Ministry building.