By Luis Enrique Martinez and Alberto Fajardo

ACAPULCO, Mexico (Reuters) - Stranded tourists salvaged belongings from submerged cars in the Mexican beach resort of Acapulco which had become a floodplain on Tuesday after some of the worst storm damage in decades killed more than 50 people across the country.

Television footage showed Acapulco's international airport terminal waist deep in water and workers wading out to escape floods which have prevented some 40,000 visitors leaving and blocked one of the main access routes to the city with mud.

A three day downpour cut off several roads in Acapulco, wrecking cars and restricting the delivery of supplies to the Pacific port city of 750,000 people where the tourist trade has suffered in recent years from a surge in drug gang violence.

"They've started to ration food here," said Pedro de la Torre, a 53-year-old graphic designer from Mexico City stranded in a large international hotel in Acapulco. "People are starting to get annoyed. I lost two cars, total write-offs," he added.

Outside the hotel, guests waded to their waterlogged vehicles in the hope of recovering whatever they could.

Since the weekend, the rains have killed more than 50 people in the states of Veracruz, Guerrero, Puebla, Hidalgo, Michoacan and Oaxaca, according to regional emergency services.

Guerrero has been the hardest hit, with some streets in the state capital Chilpancingo becoming rivers of mud and the local mayor Mario Moreno saying the city had "collapsed".

President Enrique Pena Nieto said via Twitter he had ordered a "house by house" census in Guerrero and told the federal transport ministry to establish an air bridge to Mexico City.

Local officials had considered using the airfield in nearby Pie de la Cuesta to restart flights but airline Aeromexico later said steps were being taken to transport stranded passengers directly to the tarmac of the city's airport.

Flights were due to begin again on Tuesday morning in Acapulco, where the rains have now abated.

The flooding chaos began late last week when tropical storms Ingrid and Manuel converged from the Atlantic and the Pacific, drenching Mexico in massive rainfall that has hit around two thirds of the country, according to the interior ministry.

Though both of the storms have dissipated, rain is still falling in much of country and more than 1 million people have so far been affected by flooding.

The U.S. National Hurricane Center said rain caused by the remnants of Ingrid could still produce life-threatening floods and mud slides in a large part of eastern Mexico.

Landslides have already buried homes and a bus in the eastern state of Veracruz. Thousands were evacuated from flooded areas, some by helicopter, and taken to shelters.

State oil monopoly Pemex had to evacuate three oil platforms and halted drilling at some wells. A spokesman for the company said output and exports had not been affected.

Inside Acapulco, much of the city's upscale Diamante district was flooded, with dozens of cars under water.

At least 34 people in Guerrero have so far died since the flooding swept the country, local emergency services said.

The rain had caused the state of Guerrero damages of over 5 billion pesos ($387 million), the local government said. ($1 = 12.9348 Mexican pesos)

(Additional reporting by Ana Isabel Martinez; Writing by Dave Graham; Editing by Simon Gardner and Andrew Hay)