Toll rises to at least 450 as government declares state of emergency.
The United Nations said it had mobilised almost $1m in aid from several of its agencies, while the Geneva-based International Federation of the Red Cross said it had sent two aeroplanes loaded with relief supplies.
Pope Benedict XVI called for Roman Catholic organisations to provide assistance, as groups such as Firefighters without Borders and Oxfam launched their relief efforts.
George Bush, the US president, offered his condolences and $100,000 in emergency aid, with the possibility of more to come.
The inter-American development bank said it was sending $200,000 in immediate humanitarian assistance.
Colombia is flying 20 tonnes of water, medicine, blankets and other aid, as well as supplying 20 rescue workers.
Brazil said it would send medicine, food and tents “as soon as possible”.
Alan Garcia, the country’s president, visited devastated areas on Thursday and sent condolences to the families of the victims.
The rescue of a man from the rubble of a collapsed church brought some hope to rescuers in the town of Pisco.
Carlos Cordova Gomez, chief of Peru’s voluntary firefighters, who worked under flood-lights to dig through the church ruins alongside police, soldiers and other volunteers, said: “This is virtually a miracle, hopefully we can find more”.
Felipe Aguilar, director of army rescue efforts in the town, said: “For the time being we’re going to keep on looking for bodies. For us, this is the priority right now, because we’ve already pulled one person out alive.”
The country announced it would hold three days of mourning for those who died.