Thailand grenade attack injures scores of people

Bangkok: A grenade blast wounded more than 50 protesters in Bangkok on Sunday.

The blast occurred at the prime minister's office occupied by the People's Alliance for Democracy. A spokesman for the group said 51 people were wounded, four in critical condition.

Prime Minister Somchai Wongsawat has declared a state of emergency as protesters planned a big rally to topple the government.

Protests continued at Thailand's major airports, leaving hundreds of passengers stranded.