Journalist Freed

"It is just the most fantastic thing to be free. It was an appalling experience," Johnston, 45, said in a brief telephone interview with the BBC television from the home of Hamas leader Ismail Haniya, who was dismissed as prime minister last month by Palestinian President Mahmoud Abbas after a Hamas takeover of the Gaza Strip.

The freed journalist later added "I think I'm okay." He said the ordeal was tremendously stressful.

"We are delighted and extremely relieved," the BBC said in a statement. British Prime Minister Gordon Brown also said he welcomed the news of Johnston's release.

"A friend of the Palestinian people"

Later, in a press conference just after daybreak Wednesday morning in Gaza City, Haniya described the journalist as a "friend of the Palestinian people."

Johnston said "the last 16 weeks, of course, were the worst of my life." The journalist, who was kidnapped and held by the shadowy Army of Islam, said being released was "the most unimaginable relief."

Johnston was the only Western correspondent based full-time in the troubled Gaza Strip. He said he sensed his captors felt new pressure once Hamas seized control in fighting three weeks ago.

Johnston thanked the Hamas movement, and all those who worked for his freedom.

"Appalling and terrifying experience"

Johnston said his 16 weeks in captivity was "like being buried alive" with "dangerous and unpredictable" people who "threatened my life a number of times, in various ways."

He said there was no physical violence used against him, but that at times he was mistreated. He said he was once chained for 24 hours but only in the last half hour did the captors "hit me a bit."

Johnston, who appeared pale and to have lost weight, said he fell ill twice during his captivity. The journalist added he was kept in a shuttered room for the last three months of his captivity and could not see the sun.

Johnston said he had a radio during his "appalling and terrifying experience," and was able to follow events in Gaza as well as the efforts to secure his release. He said he had dreamed many times of being freed.

"It's hard to believe I won't wake up in that room again," he said.

Prisoner swap led to Johnston's release

Earlier Tuesday night, Hamas forces had laid siege to the area of Gaza City where the Army of Islam, a group tied to the heavily armed Doghmush clan, has its stronghold and where Johnston was assumed to have been held.

"I think this is a small 'jihadi' group," Johnston said of his abductors. "I don't know the details exactly and exactly who is behind it. They had a jihadi agenda. They were not so interested in Israel-Palestine. They were interested in getting a knife into Britain in some way."

No ransom was paid, and there were no other conditions attached. The group had previously demanded Britain and other states free prisoners with ties to al Qaeda.

One week ago, a video was released in which Johnston was shown wearing a explosive vest, which he said his captors would detonate if anyone tried to free him by force.

In another statement released a day later, the group said it would "slaughter the prisoner like a sheep" if their demands were not met.

Johnston had been held captive longer than any other foreigner abducted in Gaza.