NAIROBI, Kenya -- Explosions rocked two of Somalia's largest cities on Saturday as officials said a suicide car bomber detonated near the port in Mogadishu and a land mine in a restaurant on the outskirts of Baidoa killed four people.

Ali Abdullahi, an official with the Southwestern regional state, told The Associated Press that the mine was detonated by remote control as people were dining during the morning rush. Several others were wounded, he said.

There was no immediate claim of responsibility, but the al-Qaida-linked al-Shabab group has targeted the city in the past.

In Mogadishu, thick smoke billowed over the port area after police Col. Ahmed Ali said the car bomber detonated near the gates of the motor vehicle imports duty authority headquarters.

The bomber sped through the first security checkpoint before police officers opened fire at the vehicle which exploded outside the gates, Ismail Mukhtar, spokesman for Somalia's information ministry, told the AP.

Five police officers were wounded, said Sadik Aden Ali, spokesman for Somalia's police force.

The Somalia-based al-Shabab often targets the capital with suicide bombings.