PARIS (Reuters) - French rescue workers have found two bodies in the rubble of buildings in the southern city of Marseille which collapsed following an explosion, the city's mayor said on Monday.

Authorities have previously said that nine people were believed missing after Sunday's explosion, which destroyed two residential buildings and caused a third to partially collapse. The cause of the blast is still unknown.

"This morning we are in great sorrow and pain," Marseile's Mayor Benoit Payan wrote in a tweet, adding that the rescue operations were continuing "relentlessly".

The collapse caused a fire which has complicated rescue efforts and which was continuing to burn on Monday morning.

Five people were taken to hospital on Sunday with serious but not life-threatening injuries.

Around 200 people have been evacuated from buildings near to the blast, said housing minister Olivier Klein, who was due to visit Marseille on Monday.

(Reporting by Layli Foroudi; Editing by Gareth Jones)