At least 17 people have been killed in Mozambique after a rubbish dump collapsed on nearby houses amid fears others may be buried under the mountain of rubbish.

Heavy rainfall triggered the collapse at the Hulene dump in the capital Maputo at around 3am local time (1:00 GMT) on Monday, burying five homes.

A number of other people may be trapped under the rubbish, said Leonilde Pelembe, a spokesman for the National Public Safety Service.

"The information we received from local authorities is that the number of people living in those houses exceeds the number of deaths recorded, so work is still ongoing to see if there are any other deaths," Pelembe said.

Prior to the collapse, authorities had asked residents to leave the illegally built houses in the impoverished area of the capital, Reuters news agency reported.

Rubbish at the dump had reached the height of a three-story building, according to Portuguese news agency Lusa.

People regularly visit the dump, the largest of its kind in Maputo, in search of food or items to sell.

Nearly 55 percent of Mozambique's population - about 14 million people - live in poverty, according to the United Nations Development Programme.

Maria Huo, a resident, told reporters that authorities had failed to manage rubbish levels at the dump safely. Her son was injured and her home partially destroyed in the rubbish slide.

"It's been more than 10 years that the dump should have been closed because it's full, but they still continue to pile trash on the trash. The consequence is this," Teresa Mangue, a neighbourhood leader, told AFP news agency.

Maputo City Council will open a temporary refuge centre to accommodate survivors of the collapse, Radio Mozambique reported.