BREMEN, Germany (Reuters):

Britain said yesterday it was concerned at Iranian "sabre-rattling" about possibly putting captured British naval personnel on trial and for the first time voiced regret that the incident had occurred.

Iran's ambassador to Moscow was quoted as saying the 15 Britons captured eight days ago may face trial for illegally entering the Islamic Republic's territorial waters. But he later denied having made the comments, Iran's IRNA news agency said.

Britain insists the sailors were seized in Iraqi waters and Foreign Secretary Margaret Beckett said such talk worried her.

"Obviously, I am concerned. It is not the first person to have made sabre-rattling noises," she told reporters after a European Union foreign ministers' meeting in Germany.

But she struck a conciliatory note when asked by an Iranian television reporter if she had a message for Iran, saying: "The message I want to send is I think everyone regrets that this position has arisen. What we want is a way out of it."

Beckett said Britain had sent Iran a written reply to its diplomatic note on the detention of the sailors in the Gulf but received no response so far.

Iran seized the sailors and marines in the northern Gulf on March 23 when they were on a U.N.-backed mission searching for smugglers.