Heavy rains in mountainous Oaxaca state brought a giant swathe of earth down on homes in Santa Maria Tlahuitoltepec, a town of about 9,000 people, between 3 and 4 a.m.

Oaxaca's governor, Ulises Ruiz, told local radio that seven people had been confirmed dead and 100 were missing in the landslide, which buried up to 300 houses. He had earlier estimated there could be 500 to 600 victims.

"We are told that an area about 200 meters (655 feet) wide (collapsed)," Ruiz told local TV. But other local media said hundreds more could be missing.

Civil protection authorities received a call before dawn from a resident by satellite phone, said Fausto Martinez, a rescue worker with the Oaxaca civil protection force.

"They said the mountain had collapsed and a lot of people were in their homes because of the hour," he said.

The government has sent police, marines and soldiers to the area, a four-hour drive away from the state capital of Oaxaca, the interior ministry said in a statement.

Ruiz said rescue workers were being sent to the area by plane and a Mexican Navy spokesman said a convoy of marines was en route.

President Felipe Calderon said in a message posted on his Twitter account that federal authorities were on their way, but that access was difficult to the remote region, where smaller landslides have blocked access roads in recent days.

"It just hasn't stopped raining," Ruiz told Foro TV.

Civil protection authorities in Oaxaca said the landslide was due to heavy, prolonged rains from Tropical Storm Matthew, which dumped heavy rains on Central America and southern Mexico over the weekend.

Parts of Mexico are enduring their worst rainy season on record, which has triggered heavy flooding and forced thousands of people from their homes in vulnerable parts of the country.

Tabata Anton, an official at a technical college based in Santa Maria Tlahuitoltepec, said by phone from the state capital that teachers trying to get to the area on Monday had turned around because of roads blocked by earth and rock.

She said that there had been no communication Tuesday with the institute's approximately 60 students from Santa Maria Tlahuitoltepec