A wildfire roared through parts of Israel's third-largest city on Thursday, forcing tens of thousands of people out of their homes, as the country's leaders raised the possibility that Arab assailants had intentionally set the blaze.

Spreading quickly due to dry, windy weather, the fire raced through Haifa's northern neighbourhoods. While there were no serious injuries, several dozen people were hospitalized for smoke inhalation.

In a rare move, Israel called up hundreds of military reservists to join overstretched police and firefighters and was making use of an international fleet of firefighting aircraft sent by a slew of countries.

The Haifa blaze was the most serious in a series of fires that have erupted across the country in recent days. On a visit to the area, Israeli Prime Minister Benjamin Netanyahu said anyone implicated in setting the fires would be punished severely.

"It's a crime for all intents and purposes, and in our opinion, it is terror for all intents and purposes," he said.

A firefighting plane drops fire retardant near the communal settlement of Nataf. This recent rash of fires is the worst since 2010. (Ronen Zvulun/Reuters)

He added that incitement to arson was also playing a role in spreading the fires.

Netanyahu did not elaborate on the identity or motives of the suspected arsonists, but Israeli officials typically use the term "terror" to refer to Arab or Palestinian militant activity.

Israel has been on edge following more than a year of attacks, mostly stabbings, that have tapered off in recent months, but not halted. Netanyahu has blamed Palestinian incitement for fuelling those attacks.

Netanyahu's accusations could test already brittle relations between Israel's Jewish majority and its Arab minority, which has long suffered discrimination in Israel and says it has been slighted by rhetoric from Netanyahu and other Israeli officials in the past.

'Harms all of us'

Israeli Public Security Minister Gilad Erdan told Channel 10 TV that eight people had been arrested and that authorities had found "flammable materials and liquids poured in certain areas," a find that pointed to arson. He said arson was suspected in about half of the fires.

"It's safe to assume that whoever is setting the fires isn't doing it only out of pyromania," Israel's police chief Roni Alsheich told reporters. "It's safe to assume that if it is arson, it is politically motivated."

Firefighters in <a href="https://twitter.com/hashtag/Israel?src=hash">#Israel</a> continue to battle multiple blazes but pub. safety min. now says all fires under control <a href="https://twitter.com/hashtag/cbc?src=hash">#cbc</a> <a href="https://t.co/xrEaZW54OU">pic.twitter.com/xrEaZW54OU</a> —@DerekStoffelCBC

Ayman Odeh, the head of a joint Arab bloc of parties in Israel's parliament and a Haifa native, appealed to Israelis to come together and abandon "politics" during the trying time.

"This is something that harms all of us. This is not a story of Arab or Jew. Whoever did this is an enemy of all of us," he told Israeli Channel 2 TV news.

The Palestinians meanwhile offered to send firefighting teams to help combat the flames, according to the official Palestinian news agency WAFA. Yousef Nassar, the director general of the Palestinian Civil Defence, said the offer of assistance was "a humanitarian message." Israel's response to the offer was not immediately known.

Capabilities strengthened after 2010 blaze

The Palestinians assisted Israel during a wildfire in 2010, when the country suffered the single deadliest wildfire in its history. That blaze burned out of control for four days, killed 42 people and was extinguished only after firefighting aircraft arrived from as far away as the United States.

Israel has strengthened its firefighting capabilities since then, buying special planes that can drop large quantities of water on affected areas. Several countries, including Russia, France, Cyprus, Turkey, Croatia, Greece and Italy, were also sending assistance to battle this week's blazes.

Residents of eight neighbourhoods in the northern city of Haifa were told to evacuate from their homes on Thursday afternoon, police spokesman Micky Rosenfeld said. Or Doron, a spokeswoman for the city of Haifa, said some 50,000 people had been evacuated from the area.

Police and firefighters were deployed throughout the city, as people loaded up supermarket carts with belongings and fled their homes. Some people connected hoses together from apartment buildings to help battle the fires.

People carry their belongings inside a grocery cart as they flee Haifa, Israel's third largest city. (Ariel Schalit/Associated Press)

Guy Catlan, who runs a gas station in Haifa, told Channel 10 TV that workers turned the power off and were helping firefighters to prevent the flames from reaching it. "There is a very large quantity of fuel here," he said. "It is very dangerous to the entire area, it could be a big catastrophe."

Michal Schanin, a professor at the University of Haifa, was in the middle of a lecture when she received word that she and her 70 students would need to leave. She said while the evacuation was orderly, the flood of cars fleeing the area caused a traffic jam.

"We couldn't move. If, God forbid, there would have been fire there it would have been one huge trap," she said.

Police said the blazes started early Tuesday morning at Neve Shalom, a community outside Jerusalem where Jews and Arabs live together. Fires later erupted elsewhere near Jerusalem and in the northern Israeli area of Zichron Yaakov.