Bihar to get extra poll security

India's chief election commissioner has promised extra security for the unruly northern state of Bihar during next month's parliamentary elections.

TS Krishnamurthy said in Patna, the state capital, that several leaders he had met feared trouble, particularly in areas affected by left-wing violence.

He also appointed a special observer from neighbouring West Bengal to work with observers for a fair election.

Mr Krishnamurthy was on a two-day state tour to review poll preparations.

The chief election commissioner also ordered the transfer of seven district officials following complaints of irregularities against them.

The general election is in four phases. Voting in Bihar takes place in three of them - on the 20 and 26 April and on 5 May.