Three Japanese were killed, and three others injured, in the militant attack on tourists in Tunisia, the Japanese government said Thursday.

The Tunisian prime minister said earlier that five Japanese were among the 19 victims, but an unnamed Japanese official said that after checking the report, Japan found that some of the names were overlapping, according to Japanese broadcaster NHK.

Japanese Prime Minister Shinzo Abe announced the three deaths and three injured to reporters. He strongly condemned the attack, saying that "terrorism cannot be tolerated under any circumstances."

U.S. first lady Michelle Obama, on a visit to Tokyo, said: "I want to express our condolences over the horrific events yesterday in Tunisia. Our hearts go out to the loved ones of those killed they are very much in our thoughts and prayers today."

The victims were killed by two militants who burst from a vehicle and began gunning down tourists getting off buses at a museum.