Striking for the second time in as many days in a bid to disrupt the Lok Sabha polls, Maoists on Thursday ambushed a Border Security Force vehicle, killing seven persons, including five BSF personnel, in Latehar district of Jhakhand.

A helper and civilian driver of the vehicle were among those killed in the landmine blast in the area, about 125 km from Ranchi, according to Deputy Commissioner Sarvendu Tathagat.

The bus ferrying the BSF personnel from Ladhup to Arah was blown by the landmine blast triggered by the Maoists at around 7.30 am killing five BSF personnel, one helper and the civilian driver, the DC said.

The BSF personnel were returning after patrolling.

A helicopter has flown to the spot for rescue operation, he said, adding an encounter is going on.

On Wednesday, Maoists had triggered a landmine targeting a Central Reserve Police Force vehicle killing a civilian driver. In the ensuing encounter, a CRPF constable, a sub-inspector and five Maoists were also killed.