MANILA, Dec 21 (Reuters) - A Philippine ferry carrying 251 people capsized on Thursday off an island south of Manila, the capital, a coast guard spokesman said, amid a storm bringing heavy downpours.

Three people were killed in the accident, domestic radio said. Rescue operations were hampered by bad weather and huge waves caused by a typhoon in the south.

Coast guard boats and army helicopters rushed to the vicinity of Polilio island in the province of Quezon to rescue passengers, taking advantage of daylight, spokesman Armand Balilo said on television.

“We heard about casualties, but we are still trying to get a complete picture,” Balilo said, adding that the ferry, which had the capacity to carry 280 people, had not been overloaded.

Boat accidents are common in the Philippines, which is frequently lashed by storms and typhoons. (Reporting by Manuel Mogato; Editing by Martin Petty and Clarence Fernandez)