Gunfire and explosions went off in Somalia's capital Mogadishu in the early hours of Wednesday as al Shabaab militants attacked police stations and security checkpoints, Reuters reported, citing Abdullahi Nor, the internal security minister.

Al Qaeda-linked al Shabaab, which aims to topple the central government, carries out frequent attacks against the government, including attacking a minibus carrying election delegates last week.

"The terrorists attacked the suburbs of Mogadishu and targeted our police stations and checkpoints," Abdullahi Nor wrote on Twitter. "Our security defeated the enemy." 

There were no immediate details on casualties.