NEW DELHI: India's opposition parties held a nationwide strike on Thursday, vowing to shut down the country in protest against steep petrol price rises announced last week.

Political parties and trade unions planned anti-government marches, roadblocks and pickets outside government offices to focus anger on the administration of embattled Prime Minister Manmohan Singh.

"We will lodge a strong democratic protest over the petrol price hike," Prakash Javdekar, spokesman of the main opposition Bharatiya Janata Party (BJP), told AFP.

"People are angry and they want to protest and this is the only legitimate way."

The strike called by the BJP and other opposition parties is not a threat to the Congress party-led government, but poses a fresh challenge as Singh struggles with declining economic growth and policy paralysis in parliament.

"The price rise is killing us and the government is sleeping but today will wake them up," said Ravikant Sahai, a grocery shop owner in New Delhi, where many roads were quiet on Thursday morning.

Sahai, 43, said he would not open his shop and hoped many other traders would join the strike.

"Petrol price rises hurt everyone. Our business suffers. Why is this government determined to hurt us?" he said.

Last week, Indian state-run oil firms announced the sharpest jump in petrol prices in nearly a decade to offset growing losses caused by subsidised rates, rises in the international oil price and a plunging rupee.

Once taxes are included, the price increase of 6.28 rupees (11 US cents) per litre will result in a 7.5-rupee hike for consumers in cities such as Delhi.

"It is unjustified and the government only has itself to blame for the present crisis," said D. Raja, national secretary of the Communist Party of India.

"Our demand is the oil companies must roll back the hike," Raja told AFP.

In 2010 the government deregulated petrol prices in a reform aimed at reducing the massive subsidies it pays to state-run fuel refiners which rely on imported energy.

A series of smaller petrol price increases last year caused a major headache for the government with the second-largest party in the ruling coalition threatening to pull out. -- AGENCIES