More than 670 people are believed to be dead after a massive landslide in Papua New Guinea, a U.N. official said on Sunday as aid workers and villagers braved perilous conditions in their search for survivors.

The once-bustling hillside village in Enga province was almost completely obliterated when the landslide struck in the early hours of Friday morning, burying scores of homes and the people sleeping inside them.

"There are an estimated 150-plus houses now buried," said U.N. migration agency representative Serhan Aktoprak, adding that "670-plus people are assumed dead."