KOLKATA - Opposition party workers burned buses and shut down business in eastern India's main trading hub on Monday to enforce a 12-hour strike protesting rising food prices, officials said.

However, the strike called in the state of West Bengal by India's main Hindu-nationalist opposition Bharatiya Janata Party (BJP) did not affect work in the region's main seaport of Haldia or at its coal and iron mines.

Stick-wielding BJP workers closed down offices in Kolkata, Communist-ruled West Bengal's capital, and clashed with police as they tried to stop traffic with burning tyres.

Suburban trains were stopped but flights were normal.

"They have damaged several buses and there has been sporadic trouble in some parts of the state," Surajit Kar Purokayastha, a senior police officer said.

BJP spokesman Prakash Javdekar said the strike was part of the party's nationwide protest programme under which it would try to shut down every state by turn.

Rising food prices have given a handle to the BJP, which has been riven by internal feuding after losing the May national election.

The opposition has held up parliament on the issue, delaying a debate on crucial financial reforms expected to be taken up in the current session.

India's food inflation was at 15.6 percent in mid-November as the worst dry spell in nearly four decades and annual floods in some states slashed farm output.