Polls open in India's Bihar state

Polls have opened amid tight security in the northern Indian state of Bihar.

The ruling regional leader Nitish Kumar's Janata Dal (United) leads a coalition government with the Hindu nationalist BJP in the state.

Pitted against him are a clutch of other regional parties and the Congress party.

Bihar is one of India's poorest and most corrupt states, though many believe that under Mr Kumar the state has turned the corner.

The election to the 243 seats in the assembly of the state will happen in six stages staggered over a month.

Early reports say that polling is brisk in most of the 47 constituencies which have gone to the polls on Thursday.

Mr Kumar's coalition is facing opposition from a regional coalition spear-headed by the Rashtriya Janata Dal (RJD), led by Laloo Prasad Yadav, former federal railway minister.

Mr Kumar has pledged to transform Bihar into a "developed state" by 2015, asking voters for a second term to improve its infrastructure, health, and investment profile.

His government says that Bihar clocked up a growth rate of 11.03% in 2008-2009, which would make it India's second fastest growing state economy, just behind the industrially-developed western state of Gujarat.

But critics question this claim, saying last year's economic survey - a federal government publication - showed the growth rate was just 5%.