KABUL -?Two children were killed and two other civilians were injured Monday evening when a suicide attack rocked the main gate of Bagram Airbase, north of Afghan capital of Kabul, an official said.

"Our police reported that a suicide attack occurred in front of a gate of Bagram Airbase at around 5:30 pm local time. As a result two children were killed and two civilians were injured," an official with the press office of Afghan Interior Ministry told Xinhua.

He said the potential target of the attacker might have been a military convoy of foreign troops.

Meantime, a spokesman with the International Security Assistance Force (ISAF) when approached by Xinhua confirmed the blast, saying "according to initial investigation an explosion occurred outside Bagram Airbase in eastern Afghanistan but there are no reports of ISAF casualties."

"The ISAF is gathering details and more information will be released as appropriate," the spokesman of ISAF Joint Command added.

Taliban have yet to make comments.

Thousands of Afghans staged a protest demonstration against burning of Muslim holy book Quran late last month. ?

30 people were killed and over 180 others injured during the week-long protest across Afghanistan late last month over the burning of Quran by US forces in Bagram, an incident which the coalition forces said was not intentional.

The Bagram Airbase is the main US and NATO military base located 50 km north of Kabul.