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

The blast hit around 4 p.m. local time (1130 GMT), Kabul's police spokesperson 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 evacuated from their building.

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

A spokesperson for the foreign affairs ministry did not immediately respond to requests for comment.