Blast rocks Afghan foreign ministry

Kabul
Casualties have been reported after an explosion outside the foreign affairs ministry in Kabul. -EPA

An explosion has occurred outside the foreign affairs ministry in Afghanistan's capital Kabul, causing casualties, a police official says.

The blast hit about 4pm on Wednesday, Kabul's police spokesman Khalid Zadran told Reuters. 

He did not provide details on the number of casualties.

The Taliban-run administration has faced an insurgency by Islamic State militants who have targeted foreigners at certain sites, including the Russian and Pakistani embassies and a hotel catering to Chinese businessmen.

The blast took place at a busy time of day in a heavily fortified area surrounded by checkpoints on a street housing several ministries.

A person in a nearby office who asked not to be named as they were not authorised to speak to media described hearing a loud explosion and said they were later removed from their building.

Some countries, including Turkey and China, also have embassies in the area.