It is a "disaster on an international scale," said Israeli Prime Minister Benjamin Netanyahu, according to the daily newspaper Haaretz. He called a special Cabinet meeting for Friday morning to address the crisis.
"This is a difficult hour, and we will need to learn lessons for the future, but at this moment, our only thoughts are to save lives and protect the forces that are dealing with this catastrophe," the prime minister said.
Haaretz said hundreds of people have been ordered to evacuate Damon Prison and residential homes in drought-plagued hillsides near the port city. The prison guards were rushing to assist in the rescue mission when their bus caught fire.
"The bus had no chance," a firefighter spokesman told The Jerusalem Post. "They tried to escape but were burned alive. It was a horrific scene."
Israeli Wildfire Photos
An Israeli firefighter plane helps to extinguish raging fire in the Carmel Forest, near Israel's northern city of Haifa on December 02, 2010. At least 40 people were killed when the devastating fire tore through the forest prompting Israel to call for international help to put out the blaze. AFP PHOTO/ROY EL (Photo credit should read ROY EL/AFP/Getty Images)
An Israeli firefighter plane helps to extinguish raging fire in the Carmel Forest, near Israel's northern city of Haifa on December 02, 2010. At least 40 people were killed when the devastating fire tore through the forest prompting Israel to call for international help to put out the blaze. AFP PHOTO/ROY EL (Photo credit should read ROY EL/AFP/Getty Images)
An aerial view of a raging forest fire in the Carmel Forest, near Israel's northern city of Haifa, on December 2, 2010. At least 40 people were killed when the devastating fire tore through the forest prompting Israel to call for international help to put out the blaze. AFP PHOTO/MEIR PARTUSH ==ISRAEL OUT== (Photo credit should read MEIR PARTUSH/AFP/Getty Images)
A charred bus that was carrying prison guards and was trapped in a huge forest fire sits on the road on December 02, 2010 near Israel's northern city of Haifa. At least 40 people were killed when the devastating fire tore through the forest prompting Israel to call for international help to put out the blaze. AFP PHOTO/JACK GUEZ (Photo credit should read JACK GUEZ/AFP/Getty Images)
An Israeli firefighter plane helps to extinguish raging fire in the Carmel Forest, near Israel's northern city of Haifa on December 02, 2010. At least 40 people were killed when the devastating fire tore through the forest prompting Israel to call for international help to put out the blaze. AFP PHOTO/ROY EL (Photo credit should read ROY EL/AFP/Getty Images)
An Israeli firefighter plane helps to extinguish raging fire in the Carmel Forest, near Israel's northern city of Haifa on December 02, 2010. At least 40 people were killed when the devastating fire tore through the forest prompting Israel to call for international help to put out the blaze. AFP PHOTO/ROY EL (Photo credit should read ROY EL/AFP/Getty Images)
An Israeli firefighter plane helps to extinguish raging fire in the Carmel Forest, near Israel's northern city of Haifa on December 02, 2010. At least 40 people were killed when the devastating fire tore through the forest prompting Israel to call for international help to put out the blaze. AFP PHOTO/ROY EL (Photo credit should read ROY EL/AFP/Getty Images)
An Israeli firefighter plane helps to extinguish raging fire in the Carmel Forest, near Israel's northern city of Haifa on December 02, 2010. Around 40 people are believed to have been killed in the devastating forest fire burning. AFP PHOTO/ROY EL (Photo credit should read ROY EL/AFP/Getty Images)
Israeli firefighters gather near the site of raging fire in the Carmel Forest, near Israel's northern city of Haifa on December 02, 2010. Around 40 people are believed to have been killed in the devastating forest fire burning. AFP PHOTO/ROY EL (Photo credit should read ROY EL/AFP/Getty Images)
Israeli firefighters stand close to raging fire in Beit Oren, Carmel Forest, near Israel's northern city of Haifa on December 02, 2010. Around 40 people are believed to have been killed in the devastating forest fire burning. AFP PHOTO/DAVID BUIMOVITCH (Photo credit should read DAVID BUIMOVITCH/AFP/Getty Images)
Authorities said there were around 50 guards on the bus and about 40 were killed. Seven people were evacuated and rushed to Haifa hospitals in serious condition, and three people were missing.
The head of the Haifa Police Department, Deputy Cmdr. Ahuva Tomer, was driving in a vehicle behind the bus, Haaretz said. She was critically injured.
Fanned by strong winds, the fire burned over thousands of acres, cutting power and leaving Haifa blanketed by smoke, CNN said.
"We lost all control of the fire," a Haifa firefighting services spokesman told Haaretz. "There aren't enough firefighting resources in Israel in order to put out the fire."
Defense Minister Ehud Barak ordered the military to make all its resources available to help put out the fire and rescue victims. Netanyahu's office said Greece, Spain and Cyprus had agreed to send firefighting helicopters to the scene.
The fire broke out on the first day of Hanukkah, the Jewish Festival of Lights that commemorates the Maccabees' victory in 165 B.C. over their powerful Syrian oppressors. The cause of the fire was not immediately known, but it was fueled by high winds and dry conditions. Israel has been gripped by drought for months, with no significant rainfall since spring.
Officials estimated the blaze had torched some 1,600 acres, The Associated Press said.
"The flames spread on a scale we've never seen," Haifa Mayor Yonah Yahav said, according to Haaretz.
Three prisons, a hospital and a university were evacuated, along with a number of villages. Kibbutz Bet Oren was largely destroyed by the flames, but it had already been evacuated, The Jerusalem Post said.
Evacuation orders were issued tonight for several more communities, including a neighborhood of Haifa, which is Israel's third-largest city.
"Today, our hearts are in Haifa, with the firefighters that with incredible courage are battling the flames; some of them have even been injured, along with residents of the area," President Shimon Peres said, according to Haaretz. "We are praying for a miracle. We are praying for their safety. We are praying for the fire to end."