ACAPULCO, Mexico (AFP) - Hurricane Ingrid and Tropical Storm Manuel triggered rain, landslides and floods on Mexico's east and west coasts on Sunday, killing at least 20 people and forcing thousands to evacuate before landfall.

Manuel made landfall on the Pacific side while Ingrid, a category one hurricane, was expected to reach the coast on the Gulf of Mexico on Monday, but they had already swollen rivers, flooded streets and damaged bridges.

State-run energy firm Pemex evacuated three oil platforms off the Gulf coast of the north-eastern state of Tamaulipas and shut down 24 wells, the company said on its Twitter account.

On the Pacific coast, Manuel was weakening after making landfall near the Colima state town of Manzanillo, packing top winds of almost 85kmh as it moved northwest, the US hurricane centre said in a 2100 GMT (5am Singapore time) advisory.

The storms were blamed for at least 14 deaths in the south-western state of Guerrero and six in the central states of Puebla and Hidalgo, officials said.

In Guerrero, more than 2,000 people left their homes while 21,000 households were without power, state civil protection official Constantino Gonzales Vargas told AFP.

Of the 14 fatalities, six people were killed on Saturday when their van's driver lost control due to a lack of visibility and a slippery road on their way to the resort city of Acapulco, he said.

Six others died in landslides and the collapse of walls in three Guerrero towns. Two more people drowned when they were swept away by a swollen river in the state capital Chilpancingo.

Water rose as high as one metre in parts of Acapulco, dragging cars away, while the road leading to the international airport's terminal was closed.

The city's port was shut to navigation and a warning was issued against recreational use of beaches. Two men who sailed away were reported missing.

Manuel was 20km north of Manzanillo and was expected to dissipate on Monday, but it was expected to produce life-threatening surf and coastal flooding, the Miami-based hurricane center said.

As Hurricane Ingrid crept toward the east coast, three people, including a 16-year-old boy, were killed in a landslide in Tlatlauquitepec, a mountain town in the central state of Puebla.

In the central state of Hidalgo, a nurse and her driver drowned when their car was swept away by a overflowing river as they headed to a mountain area heavily affected by days of rain, civil protection officials said.

Another woman died when a landslide struck her home.

The hurricane had already forced the evacuation of 6,000 people in the east coast state of Veracruz after two rivers overflowed their banks.

The US National Hurricane Center said at 2100 GMT that Ingrid's outer rain bands were nearing the Gulf coast and that it could slightly strengthen early Monday before reaching the coast.

The storm's center was 175km east of Tampico, with maximum sustained winds of 120kmh.

The forecasters also said Ingrid was expected to trigger a storm surge of as much as 1.5m, with "large and destructive waves."