Dramatic footage filmed in Peru's capital of Lima shows a woman struggling free from a mudslide, as a new round of unusually heavy rain kills at least a dozen people and threatens flooding.

Stunned residents watched and filmed on mobile phone cameras as Evangelina Chamorro escaped after being swept into an avalanche of mud, wood debris and farm animals, about 53 kilometres south of downtown Lima.

Ms Chamorro, 32, had just dropped her two daughters at school and was feeding her pigs alongside her husband when they were pulled into a landslide.

Armando Rivera, Ms Chamorro's husband, told RPP radio they climbed a tree but the trunk broke.

They held on to each other's hands but Ms Chamorro eventually lost her grip and got separated.

She emerged near a bridge, lifting herself from a current of wooden planks and walking toward the shore covered head to toe in mud.

"There's a person there!" an onlooker cried out.

Ms Chamorro collapsed as she reached land and was quickly carried by several men to an ambulance. She sustained only minor injuries.

The new floods and mudslides over the past three days followed a series of other storms, and officials said a total of 62 people have died and 12,000 homes have been destroyed so far this year.

Authorities said they expected the intense rains — caused by the warming of surface waters in the eastern Pacific Ocean — to continue for another two weeks.

Schools nationwide are suspending classes and in Lima the swelling Huaycoloro river swept away two trucks and threatens to destroy a bridge.

President Pedro Pablo Kuczynski said late on Wednesday that authorities were prepared to provide shelter and relief to those left homeless.

AP