MEXICO CITY, Sept 15 (Reuters) - Hurricane Ingrid and tropical depression Manuel brought heavy rains to Mexico's Gulf and Pacific coasts on Sunday, causing flooding and landslides, killing 21 people and forcing some towns to cancel national Independence Day celebrations.
Thousands of people sought emergency shelter as Manuel made landfall and bands of rain from Ingrid - churning about 110 miles (175 km) from the Gulf coast - reached land, causing rivers and streams to burst their banks.
State oil monopoly Pemex, which has most of its installations in the Gulf, said it evacuated three platforms off the coast of Tamaulipas.
Pemex said on Twitter it also closed 24 wells in the area but a refinery in Ciudad Madero, Tamaulipas, close to where Ingrid is expected to reach land, remained open.
"There is a lot of water and the rivers are full," Luis Felipe Puente, national coordinator for Mexico's emergency services, told Reuters in an interview.
Because of Ingrid, several towns in Tamaulipas canceled plans for independence celebrations on Sunday night, local media reported. Usually Mexicans flock to their town square to hear local officials give the call to arms, known as "El Grito," an echo of Miguel Hidalgo's original call to arms against the Spanish in 1810.
The combination of a tropical storm on one coast and a hurricane on the other is unprecedented, Juan Manuel Caballero, the head of Mexico's meteorological service, told a press conference. "That is what is causing all this rain."
In some areas, rainfall from the storms could total 100 centimeters (39.4 inches), which would set records for an entire hurricane season, Caballero said.
Beach resort Acapulco in Guerrero state experienced heavy flooding and 11 people died as buildings and walls collapsed under the weight of the rain, Puente told a press conference on Sunday.
Three more people died in Guerrero as a result of landslides. In Puebla and Oaxaca states, four people died in building collapses and landslides, while three people died in Hidalgo state after their vehicle was carried away by a strong current.
Hurricane Ingrid, a Category 1 storm with sustained winds of 75 miles per hour (120 km per hour), was drenching Tamaulipas and Veracruz states on the Gulf coast on Sunday, sending more than 6,000 people into emergency shelters.
In Veracruz, there have been landslides and localized flooding, but no injuries or deaths reported, local emergency services officials said.
Ingrid is expected to bring hurricane conditions to Veracruz and Tamaulipas on Monday, the Miami-based National Hurricane Center (NHC) said.
The storm is moving west-northwest at about 6 miles per hour (9 km per hour) and expected to turn west toward the coast by Monday afternoon, the NHC said.
A hurricane warning was in effect from Cabo Rojo in the north of Veracruz to La Pesca in the south of Tamaulipas.
"The center of Ingrid should be very near the coast of Mexico within the hurricane warning area by Monday afternoon," the NHC said.
On the Pacific coast, Manuel weakened to a tropical depression on Sunday evening after making landfall, but the storm was still producing heavy rains, the NHC said.