Authorities said four militants were killed after they attacked Kabul International Airport in Afghanistan on Thursday.

Reuters reported that the attack was carried out by militants armed with rocket-propelled grenades and rifles. The assault at the busy airport lasted about four hours before the militants were killed.

"Four terrorists were killed by police special forces. The area is being cleared now, there are no casualties to our forces," said Interior Ministry spokesman Sediq Sediqqi.

Officials also said that there were no civilian casualties.

The Associated Press noted that the airport was temporarily shut down after the militants occupied two nearby buildings under construction and started the attack. However, the facility reopened and is operating as normal.

Tensions are mounting in Afghanistan as a recount from the second round of the disputed presidential election is underway.

This most recent attack comes after a suicide bomber blew up a car near a busy market and a mosque on Tuesday, killing and wounding dozens of people.