The devastating blaze continues to rage through mountains in northern Israel on Saturday and it will "take a week to put out," fire service officer Boaz Arkia was quoted by The Jerusalem Post as saying during a press conference in Haifa on Saturday.

Residents in and around the third largest Israeli city has witnessed an inferno in the last three days. Broke out early Thursday in Carmel mountain range overlooking Haifa, the wildfire quickly deteriorated into a huge blaze, killing 42 people and ravaging an area of over 30 sq km.

Aside from the firefighters, large police and army forces have been deployed to battle the flames. Police have evacuated more than 17,000 people from the region.

Israeli Prime Minister Benjamin Netanyahu on Saturday spoke with Swiss President Doris Leuthard to request assistance. Greece, Britain, Russia and several other countries have sent firefighting aircraft to Israel.

An Evergreen 747 Supertanker, the world's largest aerial firefighting plane, will arrive from the U.S. on Saturday night, according to Israel's Foreign Ministry.

Over 20 foreign aircraft, along with Israeli firefighting forces, have made progress in bringing the bushfire under control, but strong wind, dry weather, and high temperature were hindering the firefighting efforts, extending the process for another one or two days, police spokesman Micky Rosenfeld said Saturday.

As to the investigation into the disaster, police confirmed that it was possibly caused by negligence rather than arson. But it was not a final conclusion and police were conducting further probe, Rosenfeld was quoted by the Post as saying.

Police on Saturday arrested two teenagers, who were suspected of being linked to negligence, reported the newspaper.

Most of the 42 casualties were caused when a bus loaded with police and prison guards heading to a security prison near the blaze lost control and turned over. The guards were trying to reach an endangered prison to help evacuate the inmates.

In addition to firefighting and army forces deployed here, hundreds of civilians with specialized skills, which include rappelling and administering first aid, have joined the rescue efforts since Thursday. Among them was 16-year-old Elad Riven, who lost his life on Thursday when fighting the blaze.