At least 14 people were killed on Tuesday when a gunman opened fire on worshippers gathered at a shrine in the Afghan capital Kabul for a Shi'ite holy day, officials said.

Thirteen civilians and one police officer died, with 36 people wounded, said Ministry of Interior spokesman Sediq Sediqqi.

Ministry of Public Health officials said at least 43 people had been injured in the incident and had been taken to hospitals in the city for treatment.

The attack began just before 8 p.m. (3:30 p.m. GMT), police said, with witnesses reporting an explosion followed by gunfire.

Initial reports put the number of attackers at three, but Sediqqi said police special forces who responded to the scene found and killed only one gunman.

Security forces at the scene had evacuated the shrine as the attack unfolded, said Kabul police chief Abdul Rahman Rahimi.

The attack occurred at one of Kabul's largest shrines as Shi'ite Muslims had gathered to observe the Ashura holy day, which commemorates the 7th Century death of a grandson of the prophet Mohammed.

The attacker was dressed in a police or military uniform, according to a police official.