LOS ANGELES (Reuters/AFP) - The California-based rock band Eagles of Death Metal was in the midst of a European tour following its fourth album release when the musicians found themselves caught up in a terror attack at the Paris concert hall where they were due to perform on Friday (Nov 14).

The concert hall was one of several entertainment sites around Paris that were targeted by gunmen and bombers, killing dozens of people in what President Francois Hollande described as an unprecedented terrorist attack.

It was not immediately clear whether the band had taken the stage before gunman stormed the Bataclan music hall in the French capital.

But early indications were that members of the band, which also goes by the acronym EODM, were safe.

The band was formed in the late 1990s by lifelong friends Jesse Hughes and Josh Homme, the group's only two permanent members.

Hughes' mother Jo Ellen Hughes, told a Reuters correspondent outside her home in Palm Desert, California, 201km east of Los Angeles, that she had spoken to her son by telephone after the attack and that he was unhurt but "very upset and shaken".

"From my understanding, I think the whole band's been accounted for," she said, adding that she was not sure about the whereabouts or wellbeing of the rest of the entourage because the band and crew became separated in the pandemonium.

Hughes's mother also said she understood the band had just taken the stage when the attack began, but she had no other details, except that the musicians were taken into protective custody at a police station afterwards.

A person close to the band confirmed that the group was onstage performing when the deadly assault began.

The Washington Post interviewed Mary Lou Dorio, mother of one member of the band, who said her son and the other members of the group escaped the concert hall as the attack began.

"It was awful," she told The Post, adding that her son, drummer Julian Dorio, had been able to phone his wife from a local police station after the ordeal.

The fate of several crew members for the band remains unknown, Ms Dorio said.

The group's United States-based publicist, Jennifer Ballantyne of Universal Music Enterprises, told Reuters by e-mail that Homme - who is known for sitting out many of the group's live shows because of multiple commitments to other projects - was not in Paris with the band on Friday.

She said that Hughes was "there", without elaborating. But a Facebook post from members of the French band Red Lemons appeared to indicate Hughes, too, was safe, saying: "We were with your mates Jesse, Tuesday, the other musicians outside, they're safe, too, they took a cab."

The mention of "Jesse and Tuesday" presumably referred to Hughes and his fiancée, porn star Tuesday Cross.

Ms Ballantyne said that another EODM member she identified as Eden Galino was reportedly safe and not inside the venue, citing a Facebook post by yet another associate that said: "Hey everyone. I just spoke with Eden. He is fine."

A statement later posted on the band's Facebook page attributed to EODM, said: "We are still currently trying to determine the safety and whereabouts of all our band and crew. Our thoughts are with all of the people involved in this tragic situation."

According to early reports, the Bataclan was believed to have been attacked by two or three gunmen, who were said to have shouted slogans condemning France's role in Syria as they went through the concert hall shooting people.

The bloodshed comes about a month after the release of EODM's fourth album, Unzipped, which was followed by the group's appearance and performance on the late-night ABC television show "Jimmy Kimmel Live!"

Homme and Hughes, both from the Southern California town of Palm Desert, met as teenagers. They perform with a wide range of other musicians who play under the EODM banner, both in the studio and in live concerts.

According to band lore, the group took its name from Homme's joking description of the Polish band Vader as "the Eagles of Death Metal", a reference he and Hughes ultimately adopted for their own musical collaboration that critics say is more in keeping with garage band rock than death metal rock.