Taliban insurgents have claimed responsibility for a co-ordinated attack on a police building in Kabul involving several suicide bombers and a car bomb.
A local police official said there was first a large explosion caused by a suicide car bomb. It was followed by several other blasts and gunfire.
A gun battle then raged for six hours, leaving at least 10 people wounded.
"A group of terrorists, two or three or four, tried to enter the traffic police building," Kabul CID chief Mohammad Zahir said.
"Two of the bombers were shot dead at the entrance and one has likely entered the building and is shooting sporadically. Our security forces are in the area."
A witness said the top floor of the building was on fire.
He described the initial explosion as "very very big - it was massive".
"There are firefighter trucks, ambulances and police all over the place. The gunfire comes from that direction and the building's top floors are on fire," he added.
The attack was the second raid inside the Afghan capital in less than a week.
A statement from the Kabul police chief, Mohammad Ayub Salangi, said six of the 10 wounded were civilians and four were members of the security services.
Taliban spokesman Zabihullah Mujahid contacted the media in a text message to say the group was behind the attack.
"Today at around 5am a large number of fedayeen (suicide bombers) entered a building in Dehmazang and are attacking an American training centre, a police centre and other military centres and have caused heavy casualties on the enemy," he said.
Last Wednesday, a squad of suicide bombers attacked the Afghan intelligence agency headquarters in heavily fortified central Kabul, killing at least one guard and wounding dozens of civilians.
All six attackers were killed in that attack on the National Directorate of Security.
Taliban insurgents, who have waged an 11-year war against the Western-backed government of President Hamid Karzai, also claimed responsibility for that attack.
Afghan police and other security forces are increasingly targets of Taliban attacks as they take a bigger role in the battle against the insurgents before Nato withdraws the bulk of its 100,000 combat troops by the end of 2014.
Despite claims by the US-led Nato force that the insurgency has been weakened, Kabul is regularly attacked.
The Taliban also remain active in their traditional strongholds in the south and east of the country, and there are widespread fears of a new multi-factional civil war once international troops leave.