Kabul - At least five Afghans were killed Friday when police fired live rounds to disperse stone-throwing protesters seeking to march on the presidential palace to demand the government's resignation following a catastrophic truck bombing.

Public anger has mounted after an explosives-laden sewage tanker detonated in Kabul's diplomatic quarter on Wednesday, killing 90 people and wounding more than 400 others in the deadliest attack in the Afghan capital since 2001.

Hundreds of demonstrators calling for President Ashraf Ghani to step down and chanting "Death to the Taliban" clashed with police near the bombing site, prompting officials to respond with live rounds, tear gas and water cannon as the protesters tried to overrun a security cordon.

"In today's protest five people died and eight others were wounded," health ministry spokesman Waheed Majrooh told reporters. Kabul has been on edge since the bombing, which highlighted the ability of militants to strike even in the capital's most secure district, home to the presidential palace and foreign embassies that are enveloped in a maze of concrete blast walls. Angry citizens have demanded answers from the government over the perceived intelligence failure leading to the assault, which underscores spiralling insecurity in Afghanistan.

"Our brothers and sisters were martyred in the bloody attack on Wednesday, and our leaders are doing nothing to stop this carnage," Rahila Jafari, a civil society activist, said during the protest. "We want justice, we want the perpetrators of the attack to be hanged to death."

Another enraged Afghan said the protests would continue until Ghani and Chief Executive Abdullah Abdullah resign.

"Day after day, innocent civilians are being killed by terrorists. If our leaders cannot restore security they should step down," he said.

Afghanistan's intelligence agency has blamed the Taliban-allied Haqqani Network for the attack.

Ghani is expected to approve the execution of 11 Taliban and Haqqani prisoners, a government source told AFP, in apparent retaliation to the assault.

The Taliban - currently in the midst of their annual "spring offensive" - denied they were involved.

The Haqqani Network, long thought to have ties to neighbouring Pakistan's shadowy military establishment, is led by Sirajuddin Haqqani - who is also the Taliban's deputy leader.

It has carried out numerous attacks in Kabul, including the 2008 Indian embassy bombing that killed almost 60 people.

With hundreds wounded, the injured spilled over into hospital hallways as people were still searching for missing relatives.

Health officials warned some victims may never be identified as their bodies were torn into pieces or burned beyond recognition.