KABUL - The Taliban warned the Afghan government on Thursday against harming any of their prisoners after reports that President Ashraf Ghani would order the execution of 11 militants on death row in revenge for the devastating truck bomb attack in Kabul.

Ghani's fragile and divided government has come under increasing pressure over its failure to provide security following a series of high-profile attacks that have killed hundreds of soldiers and civilians so far this year.

Wednesday's blast ripped through a traffic-clogged street, packed with people on their way to school or work during the morning rush hour, causing hundreds of casualties in an instant and sending a tower of black smoke into the sky.

One of the worst such attacks since the US-led campaign to oust the Taliban in 2001, it was only the latest in a grim series that has killed thousands of civilians over the years.

The Taliban have denied responsibility. But the National Directorate for Security, Afghanistan's main intelligence agency, has blamed the Haqqani network, an affiliate group directly integrated into the Taliban.

With growing public anger over the chronic lack of security, Afghan television station Tolo News reported that Ghani had signed execution orders in a repeat of last year's hanging of six Taliban prisoners after an earlier suicide attack.

Two senior Afghan officials confirmed that a list had been drawn up of prisoners, all convicted members of the Taliban or the Haqqani network, but said no order had been signed.

In a statement, the Taliban, who repeated their denial of involvement, responded to the reports by threatening retaliation against the Kabul government and the justice system in particular if any prisoners were harmed.

"The administration of Kabul will be responsible for the outcome of incidents and any kind of losses." the movement's spokesman Zabihullah Mujahid said in a statement.