Serial Killer Bartolomeo Gagliano
Italian serial killer Bartolomeo Gagliano, 55, has escaped from custody Facebook

Italian police have launched a manhunt for a dangerous serial killer who escaped from custody in the northwestern town of Genoa.

Bartolomeo Gagliano, 55, who was serving time in jail for three murders and numerous other offences, went on the run after he was allowed out on day release.

Police said Gagliano, who is mentally ill, was due to get back to his cell at Genoa Marassi prison after undergoing treatment at a local mental hospital and paying a Christmas visit to his mother.

However, upon leaving his mother's house in the nearby town of Savona, the native Sicilian hijacked at gunpoint the car of a baker who was delivering bread early in the morning.

He forced the man to drive him back to Genoa. There he eventually released the baker and left aboard a white Fiat Panda.

Security forces across the Mediterranean country have been put on high alert and police have set up vehicle checkpoints in the Genoa area. Authorities said Gagliano is "extremely dangerous".

Gagliano's murderous spree began in Savona in 1981, when he killed a 29-year-old prostitute, smashing her head with a rock.

Later arrested, he was sentenced to eight years in a criminal asylum for the mentally ill.

In 1989 Gagliano and a fellow inmate, Francesco Sedda, broke out and embarked on a killing spree.

Less than a month after the evasion the pair killed a Uruguayan transsexual, Nahir Fernandez Rodriguez, with a shot through the mouth.

Three days later on Valentine 's Day 1989 Gagliano and Sedda shot dead Francesco Panizzi, a drug addict transvestite. The two felons were nicknamed 'Valentine's killers' in the wake of the game.

Less than 24 hours later they gunned down a prostitute named Laura Baldi, who despite injuries at the neck and the face survived.

The two were later arrested and reportedly tried to justify their actions saying they targeted individuals who spread the HIV virus.

Gagliano and Sedda were remanded to another psychiatric institute. Sedda died in 1994, while Gagliano kept on exploiting generous day releases to evade, commit robberies, thefts and assaults.

He was serving the last year of a jail sentence for a series of robberies at Genoa's Marassi prison.

"We didn't see it coming," said prison warden Salvatore Mazzeo. "Lately his behaviour had much improved."