BBC Reporter's Family Desperate

British Broadcasting Corporation employee Hamadah Abu Gamar puts up a poster showing kidnapped BBC Gaza correspondent Alan Johnston at the network's office in Gaza City, Sunday, April 15, 2007. A previously unknown Palestinian group said Sunday, it had killed the British journalist kidnapped over a month ago by gunmen in Gaza City, but the claim could not be confirmed. In a statement sent to news organizations, "The brigades of Tawheed and Jihad" said it killed Johnston, 42, to support demands for the release of Palestinian prisoners held by Israel. However, the BBC and the Palestinian government both said there was no evidence to back up the claim. (AP Photo/Hatem Moussa) (Hatem Moussa - AP)

LONDON -- The parents of a British journalist kidnapped in the Gaza Strip said Monday they were going through "a desperately worrying time" following unconfirmed reports he had been killed and pleaded with his captors to end the ordeal.

The British Broadcasting Corp. said it could not confirm the claim by a previously unknown Palestinian group that said it had killed Alan Johnston, the BBC's Gaza correspondent.

"For more than a day now, we have been seeking independent verification and demanding urgent clarification from the Foreign Office and the Palestinian authorities," BBC Director-General Mark Thompson said Monday at a gathering of employees. "But right now, the report is simply rumor."

Johnston, 44, was abducted by gunmen after leaving his office in the coastal Palestinian territory on March 12. On Sunday, a previously unknown group, "The Brigades of Tawheed and Jihad," said it had killed Johnston to support demands for the release of Palestinian prisoners held by Israel.

Palestinian officials said they could not confirm the claim.

Johnston's parents said in a statement they were going through "a desperately worrying time" and pleaded for more information about him.

"We make a heartfelt appeal to anybody who may have knowledge of Alan's situation and well-being to contact the authorities in Gaza," they said. "Our son has lived and worked amongst the people of Gaza for the last three years to bring their story to the outside world and we ask every one of them to help end this ordeal."

A spokesman for Prime Minister Tony Blair said his office was working closely with the Palestinian Authority and urgently seeking further information.

Britain's Foreign Office said it was "urgently" investigating the reports he had been killed.

Foreign Secretary Margaret Beckett said the claim was "terribly distressing" for Johnston's parents.

"I very much urge anyone who has any knowledge or information that could help them to know one way or the other to come forward," she told the BBC.

More than a dozen foreign journalists and aid workers have been abducted by gunmen in Gaza in the past 18 months, often in a bid by Palestinian militants to get money or jobs. Most have been released without major physical injury within hours or days.