KABUL, Afghanistan (AP) – Militants stormed Kabul’s most popular luxury hotel Monday, killing at least six people as they hunted down Westerners who cowered in a gym – a coordinated assault that could signal a new era of brazen Taliban attacks.

The gunmen threw grenades and fired AK-47s, and one even blew himself up despite heavy security at the Serena Hotel. One American and a Norwegian journalist were among the dead, officials said.

More than 30 U.S. soldiers in a half-dozen Humvees rushed to the hotel as part of a quick reaction force, and security personnel from the nearby U.S. Embassy ran through the building looking for U.S. citizens.

“There was blood on the floor all the way to the kitchen. There was a lot of blood in the lobby,” said Suzanne Griffin of Seattle, who had been in the hotel gym at the time of the attack.

“There were empty shell casings outside,” added Griffin, 62, who was working for Save the Children.

She said she had to step over the lifeless body of a woman when evacuated from the locker room.

“Thank God I didn’t get into the shower because then we heard gunfire, a lot of it. It was very close, close enough that plaster came off the ceiling,” Griffin, her voice shaking, told The Associated Press shortly after the attack. “We all just sat on the floor and got as far as we could from any glass. … We turned our phones on silent.”

It was the deadliest direct attack on a hotel in Kabul since the fall of the Taliban in 2001.

The assailants appeared to concentrate their assault on the Serena’s gym and spa, where foreigners relax and work out at night, suggesting the militants had cased the hotel in advance.

The Taliban has targeted aid workers and civilian contractors with kidnappings and killings, but this was the most daring and sophisticated attack yet and was aimed at a prominent symbol of foreign presence in the country, apparently designed to point out the vulnerability of the Western presence.

Taliban attacks have typically targeted Western and Afghan government or security personnel, not Western civilians.

The multipronged assault began around 6 p.m., when the Norwegian Embassy was hosting a meeting at the Serena for visiting Foreign Minister Jonas Gahr Stoere. U.N. Secretary-General Ban Ki-moon described Stoere as the target of the attack.

Witnesses said they first heard gunfire, then several explosions – likely from hand grenades – and also one large blast – the suicide bomb.

“There were two or three bombs and there was complete chaos,” Stian L. Solum, a photographer from the Norwegian photo agency Scanpix, told Norway’s state radio network NRK. “When I started to walk out (of the elevator), a bomb went off a little way from me. There were shots fired by what I think was an ANA (Afghan National Army) soldier.”

The attack killed six people and wounded six, said Interior Ministry spokesman Zemeri Bashary. He spoke before news of the Norwegian journalist’s death and it was not clear whether he was counted among the six dead.

One of the militants was shot to death and a Taliban spokesman said a second died in the suicide explosion. It was not clear what happened to the other attackers.

Zabiullah Mujahid, the Taliban spokesman, told AP that four militants with suicide vests attacked the hotel – one bomber who detonated his explosives and three militants who threw grenades and fired guns. The claim could not be verified but came very soon after the attack. The bomber was not included among the count of the dead.

In Washington, two State Department officials said that one American citizen had been killed. The victim’s identity was being withheld pending notification of relatives, the official said on condition of anonymity ahead of a formal announcement.

White House press secretary Dana Perino said the attack was carried out by extremists “killing innocent people to pursue their political objectives.

“It underscores the reason we have to stay on the offense against the extremists in places like Kabul but also in other places around the world,” she said. “We’re in for a long, hard fight. These are deliberate, patient people who will murder innocents including our own people.”

There are more than 50,000 troops from at least 39 countries, including about 25,000 U.S. forces, in Afghanistan.

A reporter for the Oslo newspaper Dagbladet, identified as Carsten Thomassen, 38, died from wounds he sustained in the attack, according to the paper’s Web site. “We feel great sorrow and powerlessness,” managing editor Anne Aasheim said.

A Norwegian Foreign Ministry employee was also among the wounded but was out of danger at a Kabul hospital, officials said.

Stoere, who was in the hotel basement with a Norwegian delegation at the time, said he was about to start a meeting when the explosions hit, and everyone was ordered to get on the floor for about 10 minutes.

“I don’t think anyone could experience this without feeling you are in a serious situation,” Stoere said on the TV-2 television network.

“Our security guards undertook an armed evacuation, where we went from corner to corner in the cellar until we reached a safe area,” he told Norwegian reporters.

The U.N. secretary-general said Stoere was the target but did not say why.

“They do not care whoever, whatever. This is really a serious crime against humanity,” Ban told several reporters at U.N. headquarters.

The 177-room Serena is a newly built luxury hotel frequently used by foreign embassies for meetings, parties and dinners. The nicest hotel in the city, visiting Westerners often stay, eat and work out there. Located in downtown Kabul, it is near the presidential palace, although separated by fences, blast walls and checkpoints. It is also near several government ministries and a district police station.

On its Web site, the hotel bills itself as an “oasis of luxury in a war-ravaged city.” The Serena has a double-gated entrance for cars, several armed guards and a metal detector at the entrance.

“In the wake of this attack, the management will strive to further reinforce the security in and around the hotel to prevent further attacks and ensure the safety of its guests and staff,” the company said in a statement from Paris.

While the number of casualties from the attack could have been higher, the militants were still able to penetrate a well-guarded and high-profile target, a symbol of progress in an otherwise downtrodden capital.

The reverberations of the attack could be felt for months. While Western aid workers, embassy employees and businessmen enjoy a fair amount of freedom of movement in Kabul, security companies could now restrain their Western clients from visiting restaurants at night if the Taliban start targeting them.

Griffin had contacted the U.S. Embassy, which told her to not open the door to the room unless she heard an American voice. U.S. soldiers evacuated her, she said.

Stoere said Afghan President Hamid Karzai called to express his concern, and offered assistance, including accommodation in the presidential residence if needed.

Aftenposten journalist Tor Arne Andreassen told the Oslo paper’s Internet edition that he heard a grenade explode and looked out a window and “could see shots being fired at the guard post by the gate.”

“The plaster flew around our room and the whole building shook,” Andreassen said.

In 2003, a rocket exploded near the Intercontinental Hotel in Kabul, knocking some guests from their restaurant chairs and shattering windows. No injuries were reported.