PATNA (AFP) - Demonstrators in poverty-hit eastern India burnt tyres and blocked roads on Thursday to protest against sky-rocketing food prices, piling pressure on authorities to crack down on inflation. Police in Bihar state rounded up scores of demonstrators including protest leader Lalu Prasad Yadav, head of the main state opposition party Rashtriya Janata Dal (RJD) and a prominent figure nationally. This is the beginning of the battle against rising prices, Yadav told supporters in the state capital Patna before he was detained along with his wife. We cant accept that the poor go without food due to rising prices, said Yadav, who was arrested along with a number of other party leaders. The protests came as data released by the commerce ministry in New Delhi showed that food inflation touched 17.40 percent for the week ended January 16, driven mainly by rising prices of eggs and vegetables. Police said demonstrators set tyres alight, halted traffic on main roads and forced shopkeepers and businesses to close in Patna and other parts of the state, one of Indias poorest. The protesters also halted trains in parts of Bihar, pelting some with stones and blocking tracks. The police have arrested people who were upsetting normal life but there was no major violence, senior state police official U.S. Dutt told AFP. Dutt declined to say how many protesters were rounded up but TV reports said the number totalled thousands. They were released in the early evening, Dutt said. Food price rises have been fuelled by the most meagre annual rainfall last year since 1972 that hurt crop output in the country of nearly 1.2 billion people. The need to tame food prices has become a top priority for the ruling national Congress party with Indias hundreds of millions of poor-its key political base-reeling from spiralling rises in the cost of basic staples. The poor are facing the brunt of high food prices, Hindu nationalist Bharatiya Janata Party leader Lal Krishna Advani told reporters in the western city of Ahmedabad. The government has totally failed on the inflation front, he said. The protests in Bihar came a day before Indias central bank was to hold a regular policy meeting to decide on whether to tighten monetary policy in a bid to curb inflation. In a statement late Thursday, the central bank said inflation had become a major concern. As Indias economy recovers, the bank said the risk of food price inflation causing generalised inflation cannot be ignored. Overall inflation is running at 7.3 percent, driven mainly by food prices. Most analysts said they expected the bank to take a step toward monetary tightening by draining some liquidity from the banking system. But they expected the bank to hold off on any interest rate rises for a few months for fear of derailing economic growth which is still patchy even though it logged nearly eight percent in the second quarter. The bank has said in the past that raising rates is largely ineffective in tackling food price inflation, which is being driven by crop shortages.