After estimating up to 1,000 people might have been buried alive, officials said as many as 11 were missing, CNN reported.
Rescuers were still conducting house-to-house searches, but Ruiz said they had not found any bodiesl the Los Angeles Times reported.
Gov. Ulises Ruiz of the state of Oaxaca initially told the Televisa network, a CNN affiliate, the early-morning landslide may have buried from 100 to 300 houses and killed between 500 and 1,000 people in the small town of Santa Maria de Tlahuitoltepec, The Guardian, a British newspaper, reported.
Ruiz said the numbers were based on the first phone calls he received from people in the vicinity of the landslide.
"Fortunately, what we know about this disaster has changed radically," he said.
"We hope we will find (the missing people) alive," Ruiz said.
Ruiz said the slide followed days of heavy rain in the region and rescuers from Mexico City and elsewhere were having trouble reaching the area. CNN said a storm system in the western Caribbean caused widespread rain. More rain was forecast for the next couple of days.
CNN said Ruiz told Televisa, a CNN affiliate, that rescue workers were bringing in heavy machinery, and police and military officials were on their way.
CNN said some residents in the area were complaining Tuesday that help was slow in coming.
"Police and rescue officials still have not arrived at the landslide zone and there are many landslides on the road," a post on the Twitter Internet blogging site said, CNN reported.
Many homes are built on the edge of steep ridges in the state, which is 2,000 feet above sea level, CNN said. The terrain makes the area conducive to landslides in severe weather, the report said.
CNN Meteorologist Brandon Miller said the forecast calls for more rain in the region through Wednesday.