The attack comes as US special peace envoy for Afghanistan Zalmay Khalilzad holds a seventh round of peace talks with the Taliban Islamist militant group in Qatar
Afghan security forces were battling gunmen on Monday who had forced their way into a building in the capital, Kabul, after a bomb-laden truck exploded near a defence ministry compound during rush hour, injuring at least 65 people, authorities said.
At least three gunmen entered a building around the defence ministry after the explosives were detonated near the ministry's engineering and logistics department, a government security official said.
"Gunmen have entered a building and they are clashing with the Afghan forces after the powerful blast," said interior ministry spokesman Nasrat Rahimi. There has been no claim of responsibility yet for the blast.
As many as 65 people, including nine children, hurt in the blast were taken to hospital, said health ministry spokesman Wahidullah Mayar. There was no immediate word on fatalities.
The blast sent a plume of black smoke over the city, with Reuters witnesses saying the sound shook their office building, as sporadic gunfire and the wail of ambulance sirens pierced the air.
Clustered in the area are military and government buildings, as well as the Afghan Football Federation, whose spokesman, Shafi Shadab, said its chief, Yosuf Kargar, was among several members injured.
The attack comes as US special peace envoy for Afghanistan Zalmay Khalilzad holds a seventh round of peace talks with the Taliban Islamist militant group in Qatar, aimed at bringing an end to the 18-year war in Afghanistan.
The peace talks have focused on four issues, ranging from counter-terrorism, and withdrawal of foreign troops to an intra-Afghan dialogue and a comprehensive ceasefire.