By Henry Romero and Manuel Carrillo

BELIZE CITY (Reuters) - Tropical Storm Earl whipped Belize and Mexico's Caribbean coast with wind and heavy rain, battering cars, disrupting transportation and forcing hundreds into shelters as it moved through Guatemala toward southeastern Mexico on Thursday.

Some flights to the Mexican seaside resort Chetumal and from the city of Campeche were canceled due to Earl, which smashed car windows and punched holes in the roofs of Belize City's wooden houses, downed trees and flooded parts of the coastline.

"It was a whole lot scarier than I thought," said Philip Gray, a church member from Birmingham, Alabama, who was staying in Belize City. "The wind was very, very strong, we saw the air conditioners on the roof coming apart ... so very dangerous."

Earl had been designated a hurricane overnight, but rapidly weakened over high ground as dawn broke on Thursday, the Miami-based U.S. National Hurricane Center (NHC) said in a statement.

The storm was dumping heavy rains on parts of Central America and southeast Mexico, the NHC said. Mexico's government ended storm warnings, and floods or landslides were considered the main risk going forward.

At 1800 GMT, Earl was producing maximum sustained winds of 45 miles per hour (72 km per hour), and was some 140 miles (225 km) southeast of the Mexican port of Ciudad del Carmen.

Hundreds of people were sheltered in Belize City and parts of Honduras overnight, local authorities said.

The damage to Belize City was concentrated in impoverished areas, and residents were seen early in the day attempting repairs amid the flood waters.

Some 35 families were evacuated from the southern part of the Mexican state of Quintana Roo, chiefly in Banco Chinchorro, an atoll off the coast from Chetumal, Pedro Santos, a local emergency services official, said by telephone.

Mexican airline Interjet canceled six flights to and from Chetumal on Wednesday and Thursday. The airline TAR said it had called off some flights from Campeche.

Earl is forecast to weaken to a tropical depression later Thursday, the NHC said.

Mexican national oil company Pemex said on Wednesday night it was monitoring Earl but had not evacuated workers at oil platforms concentrated in the southern Gulf of Mexico.

The fifth named storm of the 2016 season, Earl was expected to bring 8 to 12 inches (20-30 cm) of rain in parts of Belize, Guatemala and southern and western Mexico through Friday morning, the NHC said.

(Additional reporting by Jose Sanchez in Belize City and Swati Verma in Bengaluru; Editing by Jeffrey Benkoe and Marguerita Choy)