Alan Johnston, the BBC journalist held hostage in the Gaza Strip since March has been released, saying it was "an amazing thing to be free".
Johnston has arrived in Jerusalem after being freed early on Wednesday from what he described as "an appalling experience".
Al Jazeera’s Nour Odeh said Alan Johnston had been freed by his Army of Islam captors early on Wednesday but looked frail and had lost a lot of weight in his nearly four months of captivity.
She said his release came after lengthy talks and strong pressure by Hamas on the Army of Islam group.
"It is just the most fantastic thing to be free," Johnston told BBC from Gaza, adding that it was "at times quite terrifying" not knowing when it was going to end.
"I dreamt many times of being free and always woke up back in that room… It’s an amazing thing to be free," Johnston said at the home of Ismail Haniya, the ousted Palestinian prime minister and local Hamas leader who had brokered his release.
Johnston called his 16 weeks in captivity the worst of his life and likened his experience to being "buried alive."
But he said he had followed events on a radio during most of his time as a hostage and thanked people around the world for what he called a psychological boost from their support.
Johnston was the only Western correspondent working full-time in the troubled coastal enclave when he went missing on March 12 after his car was found abandoned.
Johnston’s parents said they were relieved to hear that their son had been freed.
"We’ve seen him on the box, and it’s just incredible. It’s been a long 114 days," Graham Johnston, Alan’s father, said.
The BBC said in a statement it was "extremely relieved".
British diplomats and senior BBC officials arrived in Gaza from Israel, apparently to take Johnston home.
His captors later declared themselves to be the Army of Islam, a previously little known group with al-Qaeda-inspired rhetoric and links to one of Gaza’s powerful clans.
They issued web videos showing Johnston and seeking the release of Islamists held prisoner by Britain and other states.
Most recently, after Hamas officials threatened to free him by force from the clan’s stronghold, Johnston was shown wearing a suicide vest with the warning that he would die if that happened.
Hamas, apparently eager to show its ability to impose order in Gaza after many months of factional fighting with Fatah, had increased pressure on the hostage-takers to relent and had surrounded the group’s neighbourhood late on Tuesday.
Khaled Meshaal, the group’s exiled leader, told Reuters from Damascus: "The efforts by Hamas have produced the freedom of Alan Johnston."
Hamas fighters surrounded the area of Gaza City that is the base of the powerful Doghmush clan, one of whose leaders, officials say, is also a leading figure in the Army of Islam.
It also exchanged prisoners with the group in recent days during negotiations to free Johnston.
Hamas seized control of Gaza last month after its forces defeated those of Mahmoud Abbas, the Western-backed Palestinian president.
Abbas responded by dissolving the unity government he had run with Hamas and appointing an emergency government that has attempted to isolate the movement.