A suicide car bomber has struck at the gate of the Afghan intelligence service in the capital Kabul, setting off a blast which could be heard throughout the city centre and was followed by volleys of gunfire.
There was no immediate word on whether anyone had been killed.
The explosion happened at about noon local time and sent a plume of smoke rising into the sky. The shooting had died down about 45 minutes later, but it was not clear if there were still attackers at large.
An Associated Press reporter at the scene saw at least 10 people being taken away in ambulances. The windows of nearby shops were blown out and reporters could see the mangled wrecks of at least seven cars which had been caught up in the explosion.
An eyewitness who was injured by flying glass, Mohammad Zia, said the bomb was in a car which drove up to the gate of the intelligence agency, called the National Directorate of Security, and then detonated.
The NDS compound is surrounded by tall, thick cement walls designed to protect buildings from bomb blasts.
Interior Ministry spokesman Sediq Sediqqi confirmed only that the blast happened at an intersection near the intelligence service gate and the Interior Ministry. An NDS agent at the scene said the bomber had been targeting the agency.
A spokesman for the international military coalition in Afghanistan confirmed an explosion and small arms fire but did not provide further details.
Major Martyn Crighton said Afghan forces were responding to the attack and there was no involvement from the Nato military coalition.