The U.S. Embassy said Monday it has located a body believed to be that of an American who died during the hostage-taking at a Moscow theater.

U.S. officials found a body tentatively identified as that of Sandy Alan Booker, 49, an electrician from Oklahoma City who was visiting Moscow and had been reported missing by his friends and family.

Two Americans were believed to have been in the theater Wednesday night when Chechen rebels stormed it during the performance of a musical.

Booker was attending the show with his fiancee, Gubareva Svetlana, and her 13-year-old daughter when armed Chechen rebels raided the theater Wednesday night, said John Day, a friend of Booker's from Oklahoma.

Russian special forces stormed the theater Saturday to end the crisis, using a gas to paralyze the rebels that was also responsible for killing all but two of the 118 hostages who died in the rescue operation. Russia has declined to comment on the cause of death or give any other details.

Day said Booker traveled to Russia to see if he could speed up marital arrangements for his fiancee, who had to go through a background check before moving to the United States.

Day said he became worried when Booker did not e-mail him from Russia as promised. Then he heard on television news that Booker was among the 800 people in the theater when it was seized by Chechen gunmen during a performance of the popular Russian musical Nord-Ost, or "North-East."

In a message read on Russia's ORT television, U.S. Ambassador Alexander Vershbow expressed his sympathy to Russians — recalling their show of compassion after the Sept. 11 attacks in the United States, when hundreds of Russians paid their respects at the embassy.

"I want to tell all citizens of Russia that we deeply grieve for your victims and firmly stand shoulder to shoulder with you in the common struggle with terrorism," Vershbow said in Russian.