A loud explosion and follow-up gunfire were heard near the Afghan communication ministry in central Kabul on Saturday, officials said.
The blast occurred a day after talks collapsed between the Taliban and Afghan representatives, but no one claimed immediate responsibility. At least six people have been wounded, according to the health ministry.
“The information that we have is four attackers have placed themselves near the communication ministry and are engaged in gun battles with the Afghan security forces,” Amanduddin Shariati, a security official in Kabul said.
Security forces were engaged in an operation against the attackers inside the building, Kabul Police Chief Sayed Mohammad Roshandil said. The ministry has 2,000 employees, the Tolo News twitter account quoted him saying.
The Ministry of Communication and IT is located in downtown Kabul, about two kilometres (1.25 miles) from the green zone, close to the heavily-fortified Serena Hotel, one of the very few Kabul hotels still used by foreign visitors.
Interior ministry spokesman Nasrat Rahimi said an explosion was heard near the communication ministry around 0710 GMT (11:40 am), followed by sporadic gunfire.
Local television footage showed a small plume of smoke near the ministry, and people climbing out the windows on a lower level.
Intermittent firing could still be heard more than 30 minutes after the blast, and the area had been cordoned off by security forces.
One security official, who declined to be identified by name, said the initial blast appeared to have been caused by a suicide bomb at the entry to the ministry.
A witness quoted by the Tolo News said attackers appeared to be fighting security forces on the first floor of the ministry headquarters.
There was no confirmation from the Afghan police.