Police detained protesters in Hyderabad

Communist and opposition parties in India are holding nationwide protests against rising food and fuel prices.

The Communist-governed states of West Bengal, Tripura and Kerala are likely to be worst hit by the 12-hour strike called by the parties.

Air and train services have been disrupted in West Bengal, and attendance in offices across the states is reported to be patchy.

Food prices in India have risen by as much as 20% over the past year.

The main opposition Bharatiya Janata Party (BJP), which organised a big rally in the capital, Delhi, against the price rise is not participating in Tuesday's strike, which has been mainly called by the Communist and a few regional parties.

Reports say that the eastern city of Calcutta is worst affected with private airlines suspending services and trains held up at various places by protesters.

Toilets at the city's airport were also locked by striking workers, says the BBC's Subir Bhaumik in Calcutta.

Work in the tea gardens of West Bengal state were not affected after owners threatened to cut wages if workers did not attend, our correspondent says.

Public transport has been affected by the strike (Photo: Krishan Saith)

Transport services have also been affected in some parts of the populous northern state of Uttar Pradesh, the BBC's Ram Dutt Tripathi says.

Farm produce has fallen following droughts and floods and this has led to rising prices.

The cost of pulses, milk, wheat, rice and vegetables has gone up sharply. Finance Minister Pranab Mukherjee has said food prices are an "area of concern".

Annual inflation has also risen sharply over the past few months, from 0.5% in September to 9.9% in March, its highest level in 17 months.