Authorities in the Indian state of Jharkhand are hunting those behind a Maoist rebel attack which killed three election officials and five policemen.

The attack came half-an-hour after voting in the state closed in the sixth phase of India's general election.

The rebels set off a landmine as a bus carrying officials crossed a bridge near Asna village in the Dumka area.

The Maoists had called for a boycott of the elections, but voters ignored their call turning out in large numbers.

There were angry scenes as the bodies were brought to the local hospital, with relatives shouting "shame on you" at local officials, the BBC's Rahul Tandon reports from Dumka.

Ten people were also injured in the attack.

The Maoists, who say they are fighting for the rights of the rural poor and landless, have been described as India's biggest internal security challenge by Prime Minister Manmohan Singh.

Jharkhand is one of the states in central India where Maoists have a strong presence.

Thursday's vote was held in 117 seats in 12 states and union territories.

The nine-phase marathon election concludes on 12 May. Counting of votes is due on 16 May.

India's ruling Congress party is battling the opposition BJP to win the votes of the 814 million Indians eligible to vote.