MONTERREY, Mexico (AP) _ Thousands of people left homeless when Hurricane Gilbert destroyed their meager dwellings remain in public shelters or living in mosquito-infested debris.

''We've got serious problems,'' said Alejandro Chapa, mayor of the Monterrey suburb of San Pedro-Garza Garcia, one of the areas hit hardest by Gilbert two weeks ago.

''The No.1 problem is housing,'' he said. ''Many of the victims were victims before all this, the poverty was so bad. But what they did have was a place to live.'

Hurricane Gilbert unleashed a torrential flood in the normally dry Santa Catarina River Sept. 17.

The raging waters killed at least 141 people and left a 40-mile path of destruction through this northern capital city of 2.8 million people and communities downstream.

Most of the victims were passengers of private vehicles or five buses that police detoured from a street half a mile from the river to roads built in the riverbed. The police decision is under investigation.

''We're still finding bodies,'' said Daniel Dimas, assistant information director for Nuevo Leon state.

The savage torrent swept away streets, electricity towers and hundreds of ramshackle huts in the riverbed.

Most of the state's other rivers also overflowed, destroying more homes, while the pounding rains washed out roads and flooded communities in the surrounding mountains.

Some isolated communities still were receiving aid by helicopter this week.

Dimas said authorities didn't know how many homes the hurricane destroyed, but various reports suggest it could be more than 2,000.

At least 18,000 to 20,000 people remain in shelters throughout the region, Dimas said. Others live amid the ruins of their homes.

''We were in a shelter but they told us that those who had a house had to return. We told them it was full of mud so they gave us some crackers,'' said Antonia Jarra Torres.

''We're in the street. As long as it doesn't rain we'll survive. We can make a roof of sheets here,'' she said.

Mrs. Torres, 54, sat with her children and two grandchildren, ages 1 and 3, on the tiny strip of ground outside the dank mud-filled hut that was once their home. The family's ruined possessions lay piled up outside.

Hundreds of other poor people packed the disaster zone of the river this week, still digging through mud for possessions.

''I'm looking for a pot so I can get some water,'' Agustina Ortega said as she swung a pick into the void where her litte hut had stood.

Asked if they had insurance or savings, most people just shrugged their shoulders. ''We live one day to the next here,'' said Mrs. Ortega, 59.

Humberto Melendez, 36, an unemployed construction worker, sat with his wife and four young children outside the ruins of their former house.

''There's nothing any good here. We just came because we're just fed up with being there (the shelter),'' he said.

''There are days when I just cry all day long for the children,'' said his wife, Sanjuana.

The government said recently it would set aside land for the poor with money from public and privatte donations. Newspapers, business groups and rival politicians criticized its failure to solve the housing problem quickly.

An outpouring of donations supplied the 10 shelters still operating in the city with tons of food, clothing, medicines, diapers, stoves and mattresses.

''We don't have any complaints about the shelter. We've been treated well there,'' said Mrs. Ortega.