Twenty-two policemen have been killed in a landmine blast in the central Indian state of Madhya Pradesh.

The blast happened at 0930 local time (0400 GMT) on Sunday in the tribal district of Bastar, around 1,000km (620 miles) south of the state capital, Bhopal.

A senior police officer was among those killed in the blast, which happened as the police party followed up a tip-off about the movement of rebels in the area.

The Press Trust of India news agency reported that the landmine had been laid by members of the People's War Group.

The group targets landlords and law enforcement officials across large tracts of forest in the states of Andhra Pradesh, Madhya Pradesh, Orissa and Maharashtra.

Communist state

The rebels are waging an armed campaign for the creation of a Communist state made up of tribal areas in Andhra Pradesh and three other states in India.

Nearly 400 people were killed last year in clashes in Andhra Pradesh between the police and Naxalites - the term commonly used for left-wing groups - including 31 police officers and 200 Naxalite activists.

The People's War Group was blamed for the killing of the Madhya Pradesh state Transport Minister Likhiram Kawre in December.

His murder was said to be in retaliation for the killing earlier in the month of senior People's War Group leaders in a clash with police in the neighbouring state of Andhra Pradesh.

In a similar incident eight years ago in the Bastar district, 18 policemen were killed when a vehicle was blown up.