India 'Maoist' bomb blast kills 15 police
A landmine explosion in the western Indian state of Maharashtra has killed at least 15 policemen, officials say.
The attack has been blamed on Maoist rebels, who operate in the area as well as several other Indian states.
It is one of the worst attacks on Indian police in two years.
Maoist rebels in the eastern state of Orissa kidnapped two Italians about two weeks ago, but released one and have been in talks with the state government over the other man's release.
Tuesday's attack happened in Maharashtra's Gadchiroli district, a remote and relatively undeveloped part of the country.
The district is on Maharashtra's border with the central state of Chhattisgarh and is a stronghold of the rebels.
The police vehicle was travelling through a forested region when the landmine was triggered, reports said.
The policemen, members of India's national paramilitary force, were travelling on a bus, the Press Trust of India news agency quoted officials as saying.
The explosion was so powerful that it could be heard several kilometres away and the bus was turned into a mangled heap of twisted metal, a police officer in the district told the BBC.
"Fifteen CRPF [Central Reserve Police Force] are dead," a spokesman for the force told AFP news agency.
"The attack happened around 11:30 am (06:00 GMT) when the bus carrying them struck an IED," the spokesman, BC Khanduri said.
"The injured are now being taken to hospital. We don't have an exact estimate for the number of injured yet."
Other reports said 15 police were injured.'Red corridor'
India's Maoist insurgency began in West Bengal state in the late 1960s and has become, according to Prime Minister Manmohan Singh, the country's "greatest internal security challenge".
The Maoists control large areas of several states in a "red corridor" stretching from the north-east to central India.
They say they are fighting for communist rule and greater rights for tribal people and the rural poor.
Big military and police offensives in recent years have pushed the rebels back to their forest strongholds and levels of violence have fallen. But hit-and-run attacks are still common, killing hundreds of people every year.
Twelve policemen were killed in a landmine attack on 21 January in eastern Jharkhand state and, in June 2010, 26 police were killed in an ambush in the central state of Chhattisgarh.
In the biggest Maoist attack on security forces, 75 policemen and one driver were killed in April 2010 when the rebels ambushed a large group of paramilitary police returning from a patrol in the dense jungle of Chhattisgarh's Dantewada district.