Fighters from Somalia's al Shabaab group detonated a car bomb and fought their way into a compound where national intelligence agency officials train, police and the militants said today, as gunfire raged inside.

Sheikh Abdiasis Abu Musab, al Shabaab’s military operations spokesman, told that the fighters had captured the building and "killed many" intelligence agents inside. "First they hit a car bomb against the gate of the house and then fighters went in the building. Fighting is now going on," Major Nur Hussein, a police officer, told.

Hussein said the compound, close to the headquarters of Somalia's national intelligence agency, was also "used by the national security forces for training and lodging".

Al Shabaab wants to topple a Western-backed government in Mogadishu and has in the past stepped up attacks during the Muslim fasting month of Ramadan, which began on Wednesday.

The group on Saturday attacked a police post near the capital, killing eight officers.