An avalanche of mud and rocks has crashed into a hotel during a wedding celebration in southeastern Peru, killing at least 15 people, authorities say.

Civil defence chief Jorge Chavez said that dozens of people who had been dancing were caught under the collapsing wall and a roof early on Sunday at the Alhambra hotel in the Andean city of Abancay.

Chavez told RPP radio that at least 30 people had been pulled from the debris with injuries and were being treated at a nearby hospital.

Evaristo Ramos, the mayor of Abancay, said about 100 guests had been invited to the wedding party on Saturday and "there are 15 dead and 34 injured".

Thirteen people died immediately after the wall collapsed under heavy rains.

Firefighters, police and residents worked through the night to rescue people still trapped under rubble.

Authorities said the Alhambra hotel was built very close to a hillside. A retaining wall collapsed, and the mudslide brought the hotel roof down on the party-goers below, they said.

People searching for missing relatives were urged to visit surrounding health centers to find and identify their loved ones.