JERUSALEM - Israeli officials last night said an inferno that has raged for four days in a northern Israeli forest was largely under control by nightfall, helped in part by the world's largest flying fire extinguisher - a Boeing 747 from the U.S. carrying 20,000 gallons of water and fire retardants that joined the efforts yesterday.

Two teenage brothers were arrested Saturday in connection with the country's worst forest fire, which has killed 41 people, most of them prison guards whose bus was trapped by the flames while they were en route to evacuate a prison. The blaze has been tearing through the Carmel forest near Israel's third-largest city, Haifa, since Thursday.

Officials spoke optimistically for the first time yesterday about taming the blaze. Police spokesman Micky Rosenfeld said: "Almost all of the fire is under control."

"The general picture is better, more optimistic," firefighters' spokesman Boaz Rakia told a news conference, but warning, "It will take days to extinguish the fire completely."

Rosenfeld said there have been 20 arson attempts in other forests over the past 48 hours, and four people have been arrested.

Meanwhile, Israeli officials came under sharp criticism for their handling of the country's deadliest wildfire ever, prompting critics to ask whether the nation's leaders can cope with more serious challenges, like rocket attacks and a nuclear-armed Iran.

The sight of bumbling leaders and overwhelmed rescuers turning to the outside world for help sparked anger over the vulnerability of a nervous - and densely populated - home front.

Israel has long prided itself on its ability to minimize civilian casualties in times of conflict. But just four years after a devastating war against Lebanese Hezbollah guerrillas, in which the civil-defense system was caught off guard by waves of rocket fire, the nation still appears ill-prepared to handle its next disaster.

"We are entitled to expect of our governments not to be smart only after the fact but - at least once - to be smart before disaster strikes," Nahum Barnea, the nation's pre-eminent newspaper columnist, wrote in the Yediot Ahronot daily. "That hasn't happened because we have no national leadership here that is capable of rising above the immediate problems."

Israeli media are pointing fingers at a number of officials, including Prime Minister Benjamin Netanyahu and Interior Minister Eli Yishai, a politician from the ultra-Orthodox Shas party whose office oversees fire services. Yishai made a handy target because his party is widely despised by Israel's secular Jewish majority.

But there was little expectation heads will roll.

The blaze, believed to be the result of negligence by two teenagers smoking a water pipe, broke out on Thursday, and quickly spread because of unseasonably hot and dry conditions. A 20-square-mile area, about half of the Carmel forest, a popular nature spot on the outskirts of Haifa, has been torched, and 17,000 people were evacuated from their homes.

Throughout the crisis, Netanyahu has been in damage-control mode. Over the Jewish Sabbath, when his office is usually silent, the prime minister's staff bombarded reporters with 35 telephone text messages informing them of his every move and meeting.