By Manikant Thakur BBC correspondent in Patna

Police in the Indian state of Bihar say at least five prisoners were killed when police tried to end a siege at the Chhapra district prison.

Bihar's police chief, R.R. Prasad, told the BBC that the inmates were killed when police opened fire to disperse more than 1,000 prisoners who had taken over the complex.

At least 400 policemen are involved in the operation.

The inmates are protesting against the decision to move five fellow prisoners - all charged with serious criminal offences - to jails further away.

The revolt began on Wednesday night when the prisoners were let out of their cells to take exercise in the prison compound.

They drove about 50 unarmed guards out of the complex, and then locked themselves in.

Jail officials held several rounds of negotiations with the inmates in an effort to end the deadlock.

Police were called in after talks failed.

This is the latest in a series of security lapses in Bihar's prisons.

Inmates on the run

Last month, 11 inmates - including three convicted for serious crimes - escaped from the state's Jamui prison after setting off bombs inside.

An inquiry was launched, but none of those who fled have been caught so far.

Most jails in the country are similarly structured - with security guards inside the prison complex with little or no arms.

Bihar is considered to be one of India's most lawless states with a very low rate of conviction for lawbreakers.