Three Japanese were killed and another three were injured in a terrorist attack on Tunisia’s national museum, the government confirmed Thursday.

According to government sources, the three victims are all women: Machiyo Narusawa, 66, of Arakawa Ward, Tokyo; Chiemi Miyazaki, 49, and Haruka Miyazaki, 22, both of Sayama, Saitama Prefecture. The relationship between the two Miyazakis could not immediately be confirmed.

Two gunmen wearing military uniforms reportedly opened fire on tourists, including visitors from Japan, Italy, France, Australia, Colombia, Poland and Spain, as they got off a bus at Bardo National Museum.

The gunmen then chased the visitors inside the museum, according to Tunisian Prime Minister Habib Essid. The attackers were eventually killed by police.

“I was crouching down, putting my hands on my head. Then I was shot in the ear, neck and hand,” said Noriko Yuki, one of the three injured Japanese, in an interview with NHK.

“My mother was shot in the neck. She couldn’t move by herself when police came,” Yuki, 35, said in the interview, which aired Thursday.

“(We) heard sounds of gunshots from outside, and I was told by a guide to move from a room (of the museum). Then we heard gunshots from behind, everybody started running, we fell over and were shot,” Yuki said.

She continued to hear gunshots “for quite a while,” she said.

Essid initially said five Japanese were among 17 foreign tourists killed in the attack. But during a news conference in Tokyo on Thursday, Chief Cabinet Secretary Yoshihide Suga said that information was erroneous.

Later in the day, the Tunisian government said the death toll rose to 21, including 18 foreign tourists and three Tunisians.

Suga declined to reveal the names of the dead or injured, saying the government had not obtained permission from the families of the deceased or from the survivors.

He said the central government had no information yet about the motive for the attack, pointing out that no organization had claimed responsibility.

“Whatever reasons there might be, terrorism is never tolerable. We strongly condemn (the attack),” Prime Minister Shinzo Abe told reporters.

“We will make every effort in the fight against terrorism while deepening cooperation with the international community,” he said.

Tunisia’s capital city was considered to be relatively secure, as the country’s democratic reform movement was widely seen as one of few successes of the Arab Spring revolutions, which started in Tunisia at the end of 2010.

On Thursday, the Japanese Foreign Ministry posted a notice on its website urging people traveling to Tunisia to venture outdoors as little as possible. It also advised travelers to be particularly careful in public places that could be a terrorist target, such as government, military or police facilities, major tourist sites, department stores and street markets.

U.S. first lady Michelle Obama, who is currently visiting Japan, expressed her condolences for those killed in the attack, including the Japanese nationals.

“On behalf of myself and my husband I want to join in with the others to express our condolences over the horrific event yesterday in Tunisia,” she said at an event Thursday in Tokyo.

“Our hearts go out to the loved ones of those who were lost here in Japan and around the world.”

Information from Kyodo added