Voters in India's most populous state went to the polls Saturday in the first round of a seven-stage ballot to be spread over the next month.

At stake are 403 seats in the Uttar Pradesh state assembly, with the ruling Samajwadi Party and the Bahujan Samaj Party running even, according to opinion polls.

About 16 million people are eligible to vote in the state, which has a population of 170 million.

Tens of thousands of police were deployed for the election. Previous votes have seen violent clashes between supporters of rival parties and candidates.

Northern India's Uttar Pradesh state is among the country's least developed regions with considerable crime and corruption.

Some information for this report was provided by AFP, AP and Reuters.