A family of three was killed when a residential building collapsed in south-western Germany following a gas explosion, police said on Thursday.

Three people aged 33, 30 and 6 were found buried under the rubble following an hours-long search operation, it said.

The cause of the explosion in the town of Albstadt remained initially unclear.

The gas supply for the entire street has been cut off and there is no risk of further blasts, Mayor Roland Tralmer said earlier.

More than 200 emergency forces and sniffer dogs were deployed to the scene following the explosion early on Thursday morning.

Several neighbouring homes were also severely damaged by the blast.

Police said those affected have been evacuated and were not harmed.

Some of the houses were deemed to be still inhabitable following an initial inspection, according to the mayor.