Explosions and gunfire at a popular restaurant near the beach in Somalia's capital have killed at least two people and injured four others, according to witnesses.

The incident at the Lido Seafood restaurant erupted late on Thursday evening.

Reports indicate that more than 20 people are stranded inside the restaurant, and that gunfire and hand grenade explosions were continuing.

"I can see two dead bodies and four injured people lying on the floor of the restaurant. The injured are seriously wounded and in a pool of blood.  The main explosion occurred at the front door. I cannot tell the casualty outside," a journalist was quoted as saying by Voice of America.

Mohamud Hared, the owner of the nearby Indian Ocean Restaurant, said that he heard gunfire and then two separate explosions followed.

VOA reported that government security forces have sealed off roads to and from the restaurant and ambulances carrying injured people could be seen coming out of the area.