Officials in Afghanistan say armed men wearing suicide bomb vests stormed a police building in the eastern city of Khost.
The BBC reported on Sunday that Afghan security forces surrounded the building and had been engaged in combat with the gunmen for several hours.
At least three policemen were killed.
The gunman stormed a traffic police building at the edge of the city in the early hours of the morning.
It's thought that some of attackers were wearing suicide vests.
Local officials have said they're holding back from a full assault for fear of setting off the explosives.
The Taliban said it carried out the attack.
It comes a day after a suicide bomber killed six people and wounded another 23 at a military hospital in the Afghan capital, Kabul.
The Taliban also claimed responsibility for that attack.