About 40 people have died in what is thought to be Israel's largest ever forest fire, police have said.

警方称，一场可能是以色列历史上最大的森林大火造成大约40人死亡。

Many of the victims were prison guards travelling on a bus which was caught in the inferno（阴间，地狱） in the Carmel Mountains near the northern city of Haifa.

Thousands of people, some of them prison inmates, have been evacuated（疏散，撤离） from the area.

Scores more have been injured, the ambulance service said. The cause of the blaze was not immediately known.

Israel's Prime Minister Benjamin Netanyahu, who has visited the affected area, said it was an "unprecedented disaster".

'Horrific scene'

The Israeli prison service said the bus was carrying guards to help with the evacuation of nearby Damon Prison, which was threatened by the blaze.

The men had been raced to the area from central Israel to assist in the rescue, prison service spokesman Yaron Zamir said.

A fire brigade（消防队） spokesman told the Jerusalem Post that the flames had travelled 1,500m (4,920ft) in less than three minutes.

"The bus had no chance. They tried to escape but were burned alive. It was a horrific scene," the spokesman told the newspaper.

He called it a "difficult, sad and incomprehensible（费解的，不可思议的） day."

A senior police chief from Haifa who was also in the area was reported to have been critically injured.

There were reported injuries among prison inmates.

"We are harnessing all the forces of the state to deal with this disaster and rescue those who are injured and to stop the fire," Mr Netanyahu said.

He said protecting life was now the priority.

"We don't want any more injuries, any more dead. We suffered a hard blow and we don't want any more dead, not even one."

In a rare request for foreign assistance, Mr Netanyahu called on Greece, Italy, Cyprus and Russia to help in tackling the fire. US President Barack Obama has also offered to help.

The fire in the northern Carmel region broke out about midday (1000 GMT), and hundreds of firefighters were battling the flames on the ground and from the air amid heavy winds.

Emergency crews from across the country tried to reach the scene, weaving through heavy rush-hour traffic as night fell.

"We're on a road that takes you down Carmel Mountain and everything is burning on both sides," a paramedic supervisor from the ambulance service, Erez Geller, told the BBC.

"It's dark now and this makes it very complicated with the fire. It's a catastrophe because we have so many fatalities.

"We have had several fires in the last 10 to 12 years but nothing like this," Mr Geller said.

At a ceremony marking the Jewish festival of Hanukkah, Israeli President Shimon Peres praised the firefighters tackling the flames, saying they exemplified "personal and superior bravery"

"We pray for their safety. We pray for the cessation（停止，中断） of the fire," he said.

Some 12,000 people have been evacuated from the area.

Israeli media said it was the biggest forest fire in the country's history, with 7,000 acres (2,800 hectares) of land destroyed by Thursday evening.

Israel is currently suffering a period of drought（干旱，缺乏） with no significant rain since the spring.