An ambulance packed with explosives blew up in a crowded area of Kabul on Saturday, killing at least 95 people and wounding 158 others, officials said, in an attack claimed by the Taliban.

The explosion — one of the biggest since a truck bomb ripped through the Afghan capital's diplomatic quarter on May 31 last year — triggered chaotic scenes as terrified people fled the area where several high-profile organisations, including the European Union, have offices.

Health ministry spokesman Waheed Majroh told AFP that the toll “now stands at 95 dead, 158 wounded”, shortly after the interior ministry warned that an earlier death toll of 63 could rise.

Members of the EU delegation in Kabul were in their “safe room” and there were no casualties, an official told AFP.

An AFP reporter saw “lots of dead and wounded” civilians in the nearby Jamhuriat hospital where overwhelmed medical staff struggled to treat bloodied men, women and children lying in corridors.

Earlier, health ministry spokesman Waheed Majroh had told AFP that the toll from Kabul hospitals stands at 40 killed and 140 wounded.

The force of the blast shook windows of buildings at least two kilometres (more than a mile) away and shattered windows within hundreds of metres of the site.

Some low-rise structures in the vicinity of the explosion also collapsed.

“The suicide bomber used an ambulance to pass through the checkpoints. He passed through the first checkpoint saying he was taking a patient to Jamhuriat hospital and at the second checkpoint he was recognised and blew his explosive-laden car,” interior ministry deputy spokesman Nasrat Rahimi told AFP.

The Taliban claimed responsibility for the attack on social media — their second deadly assault in Kabul in the span of a week.

'Massacre'

The Italian NGO Emergency said seven dead and 70 injured had been taken to its hospital, with its coordinator Dejan Panic tweeting that it had been a “massacre”.

Outside civilians walked through debris-covered streets carrying wounded people on their backs as others loaded several bodies at a time into ambulances and private cars to take them to medical facilities around the city.

Aminullah, whose stationery shop is just metres from the site of the blast, said the force of the explosion shook the foundations of his building.

“The building shook. All our windows broke. The people are in shock in our market,” he told AFP.

Photos shared on social media purportedly of the blast showed a huge plume of smoke rising into the sky. A man told Tolo News he was passing the area when the explosion happened.

“I heard a big bang and I fainted,” he said, outside the Emergency hospital.

“There were dozens of people who were killed and wounded. There were pools of blood.” The explosion happened in a busy part of the city where the High Peace Council, which is charged with negotiating with the Taliban, has offices.

“It targeted our checkpoint. It was really huge — all our windows are broken,” Hassina Safi, a member of High Peace Council, told AFP.

“So far we don't have any reports if any of our members are wounded or killed.” Members of the European Union's delegation in Kabul were in their “safe room” and there were no casualties, an official told AFP.

The explosion comes exactly a week after Taliban militants stormed a luxury hotel in Kabul, killing at least 22 people, the majority foreigners.

A security alert issued to foreigners on Saturday morning had warned that the militant Islamic State group, which has terrorised the city in recent months, was planning “to conduct aggressive attacks” on supermarkets, shops and hotels frequented by foreigners.

Pakistan condemns attack

Islamabad has strongly condemned the terrorist attack in Kabul.

"We express deep grief and sorrow at the loss of precious human lives in this terrorist attack in which a number of people have also been reportedly injured," a statement issued by the Foreign Office (FO) said.

"Pakistan reiterates its strong condemnation of terrorism in all its forms and manifestations," it added. The FO also emphasised the need for concerted efforts and effective cooperation among the states to eradicate the scourge of terrorism.