A squad of 20 riot police stormed a commandeered jetliner minutes before dawn today, seizing the lone hijacker and freeing 364 people who had endured 15 hours of captivity on a runway in northern Japan.

The ordeal aboard the All Nippon Airways Boeing 747 jumbo jet at Hakodate airport on the northern island of Hokkaido produced no serious injuries to passengers or police. One female passenger apparently suffered a mild stab wound in the shoulder from the long, sharpened screwdriver that was the hijacker's only weapon, police said.

Police disclosed a few details about the hijacker today, including his name, Fumio Kutsumi, his age, 53, and his occupation -- he had held a job in a small Tokyo bank but had been placed on a year's leave of absence -- and they were quick to announce that he evidently had no relationship to Aum Supreme Truth, the secretive cult whose members have been charged with a series of terrorist crimes this spring.

When Kutsumi took over ANA Flight 857 about noon Wednesday, he initially said he was acting on behalf of Shoko Asahara, the Aum guru who has been jailed on murder charges. The claim raised anew fears that Japan's reign of terrorism was not yet over.

Kutsumi was evidently able to capitalize on the lingering fear of Aum to hold the plane as long as he did. He claimed to have henchmen seated in the aircraft, and authorities were worried that he might also have a bomb or a packet of poison gas such as Aum members allegedly used in two cases of mass murder.

Kutsumi reportedly held his screwdriver at the neck of a flight attendant, threatening to kill her. He stormed around the plane raving and shouting, passengers said. "He came over and screamed at me, Are you ready to die?' " an elderly woman recalled.

After hours of failed efforts to negotiate with Kutsumi, authorities finally concluded that he was probably acting alone and decided to storm the plane. The raid came at 3:42 a.m. (2:42 p.m. Wednesday, EDT) -- just in time, because sunrise came at 4:02 a.m. in Hakodate, at the far eastern edge of the Japan standard time zone.

The Japanese fascination with high-tech gadgetry proved a key ally for authorities. Numerous passengers on the flight had fold-up, pocket-sized cellular phones, police said, and Kutsumi could not stop them all from placing calls. Reports from these passengers helped authorities realize that they were dealing with just one hijacker.

"The hardest thing for us," government spokesman Kozo Igarashi said after the successful raid, "was determining that he was in fact acting alone, and whether or not he had a bomb."

According to media reports here, police had been arguing for hours that a quick raid could solve the case. But in this highly centralized nation, any decision as important as that one must be referred to the national government in Tokyo. Prime Minister Tomiichi Murayama and members of his cabinet did not agree until 3 a.m. to authorize the raid -- leaving a fairly small interval of darkness before sunrise.

Stealthily, small groups of police dressed as airport maintenance workers approached the plane, while a stewardess tried to distract Kutsumi inside.

One contingent opened a gate behind the plane just before a larger force moved in. Some police were wearing chemical-protection gear while others carried riot shields.

The riot police scaled ladders to three doors of the plane, rushed in and grabbed Kutsumi before he could strike out at anyone. He was hustled from the plane, his arms bloodied and his head swathed in a towel. Within 20 minutes of the police attack, passengers were filing quietly to buses lined up on the runway, some carrying tiny babies wrapped in blankets.

The plane's pilots were seen shaking hands. "I am very glad," a relieved Murayama told reporters afterward, "especially because I heard there were babies and a 92-year-old man aboard the plane. I was only thinking of this."

Flight 857 from Tokyo to Hakodate was scheduled to be a quick mid-afternoon trip, and Japan's deficit-plagued airlines rarely provide in-flight meals these days on domestic flights. Accordingly, there was almost no food or drink aboard the plane, and Kutsumi refused to permit any resupply during the 15 hours the plane sat on a runway at the small airport.

He also reportedly banned use of bathrooms, but some passengers moved around the plane anyway.

It was not clear how a single hijacker was able to take over the flight. Initial reports said that he was seated in the second-floor cabin, where a single flight attendant is stationed.

Kutsumi reportedly grabbed the attendant and held his screwdriver to her throat, threatening to kill her. At his command, other stewardesses then taped the mouths and hands of passengers -- but did it so lightly that most were able to free themselves.

In a series of demands relayed through the pilot and flight attendants, Kutsumi reportedly said that "I did this for Asahara." That comment prompted fears here that the hijacking was carried out by the Aum cult to pressure authorities into releasing Asahara from jail.

The cult leader faces life imprisonment or a death penalty if he is convicted of masterminding this spring's poison gas attack on the Tokyo subways, which left 12 dead.

In two previous hijacking cases, in the 1970s, Japan's government gave in to terrorist demands, releasing prisoners from jail in order to save hostages. A popular magazine, Shukan Post, ran a major story this week relating those cases and speculating that Aum might try a hijacking to win Asahara's release.

Aum officials here denied that their cult had any connection to the hijacking. As the hours wore on, Kutsumi also reportedly denied that he was an Aum member. When he was captured, Kustumi initially refused to give his name or address or any reason for his crime, police said. He had just one thing to say: "I'm sorry." Later, according to television reports, the police asked again. "I did what I did," he reportedly told them. CAPTION: Police storm the jet early today, top, seizing the hijacker and freeing passengers. At left, Fumio Kutsumi, his head in a towel, is led from the jet. CAPTION: Rescued passengers wait in a bus after they were freed from the hijacked plane in northern Japan. (Photo ran in an earlier edition) CAPTION: Police lead away hijacker, his head in a towel, after they stormed the plane. (Photo ran in an earlier edition)