(Adds details, background) By Firouz Sedarat DUBAI, June 1 (Reuters) - Kidnapped BBC Gaza correspondent Alan Johnston said his captors had treated him well in an Internet video issued by them on Friday. The undated video, posted on an Islamist Web site, is the first time Johnston has been seen or heard in public since he was seized on his way home from work on March 12. "First of all, my captors have treated me very well," he said on the video issued by a group called the Army of Islam which last month claimed responsibility for his kidnapping. "They have fed me well, there has been no violence towards me at all and I'm in good health," said Johnston, wearing a red sweater and sitting against a dark grey background. The group repeated its demand on the video for Britain to free Muslim prisoners, particularly the Islamist cleric Abu Qatada. In London, a British Foreign Office spokesman said: "We are urgently trying to check out the reports." The video, posted on an Islamist Web site often used by al Qaeda and other militant groups, was accompanied by what appeared to be a picture of the first page of Johnston's passport. Johnston, who turned 45 in captivity last month, is the only Western correspondent based full-time in Gaza, where a year-old economic embargo and fighting among militants have worsened living conditions for the 1.4 million people crammed into the territory and heightened instability. He has been held far longer than other Western hostages in Gaza. Palestinian officials had often said they believed he was safe and well, but an e-mail in the name of another group had said in April Johnston had been killed. Abu Qatada has been described by the British government as a "significant international terrorist" with suspected close links to al Qaeda. He is one of more than a dozen Arab men whom Britain has been holding under detention or house arrest as threats to national security, while acknowledging that it does not have sufficient evidence to put them on trial. "In all this, you can see the British government is endlessly working to occupy Muslim lands against the will of the people in those places," Johnston said. He criticised the British military presence alongside the United States in Afghanistan and Iraq. The tape was interrupted as Johnston started addressing his family members, and a text appeared in which the group said the BBC had refused to take Johnston's message to his family, without elaborating. It was again interrupted as Johnston was about to list the captors' demands for his release. What followed was part an audio tape issued by the Army of Islam on May 9 demanding the release of Abu Qatada and other Muslim detainees in Britain and other "infidel" countries. Some 100,000 people have signed a BBC online petition calling for Johnston's release. Saeb Erekat, an aide to Palestinian President Mahmoud Abbas, called the kidnappers "gangsters" who were harming the Palestinian cause and told the BBC in a telephone interview Gaza authorities had to free Johnston, even if it entailed some kind of security operation.
