Jill Carroll, an American freelance reporter, was freed today almost 12 weeks after being abducted at gunpoint on a Baghdad street but said that she still had no idea why she was kidnapped or by whom.

Ms Carroll, 28, was delivered this morning to an office of the Iraqi Islamic Party in Baghdad's Amriya district, a stronghold of Sunni Muslim insurgents.

"I was treated well - they didn’t hit me or threaten me - but I don't know why I was kidnapped," Ms Carroll said. "I am happy to be free. I just want to be with my family quickly."

In a brief interview with Baghdad Television, a station run by the party to which her captors gave her up, the journalist looked composed and in good health. She was wearing a light green Islamic headscarf and a grey Arabic robe.

She said that she had a comfortable room and was able to wash when she wanted, but did not know where she was held. Only once was she allowed access to a newspaper.

Asked who had kidnapped her and why, she said, in remarks translated by the station: "I don’t know. You should ask the mujahideen."

Ms Carroll, who had lived in Iraq since October 2003 working for the Boston-based Christian Science Monitor, was seized on January 7 by armed men who shot dead her interpreter. The abduction embarrassed Sunni Muslim leaders since she had just left an appointment to interview a leading Sunni politician when she was seized.

Her release comes a week after an SAS-led force rescued three Christian peace activists, including Norman Kember, a retired professor from North London. Yesterday Ms Carroll's twin sister Katie made an emotional appeal for her freedom broadcast on an Arabic television station.

Soon after her release she was taken to the fortified Green Zone in central Baghdad, which houses government ministries and the US and UK embassies and delivered into the care of US officials.

Ms Carroll's father Jim, with whom she spoke soon after her release, told reporters on the porch of his hom in Chapel Hill, North Carolina: "Obviously we are thrilled and relieved that she has been released. We want to thank all that have supported and prayed for her."

The reporter had appeared in three videos broadcast on Arab television since her abduction while her captors, which called itself the Brigades of Vengeance, set numerous deadlines threatening to kill her if US-led forces failed to release all female detainees in Iraq.

Bayan Jabr, the Iraqi Interior Minister, said last month that Ms Carroll was in fact being held by the Islamic Army in Iraq, the insurgent group that held two French journalists for four months.

Yesterday, Katie Carroll had appealed for her sister's release on the Dubai-based al-Arabiya television. "It has been nearly two months since the last video of my sister was broadcast. We have had no contact with her nor received any information about her condition," she said.

"I’ve been living a nightmare, worrying if she is hurt or ill. There is no one I hold closer to my heart than my sister and I am deeply worried wondering how she is being treated. No family should have to endure having their loved one taken away from them in this way."

She said that after three years in Iraq Jill "has many Iraqi friends, and respects their culture".

She added: "My sister has always had special praise for the strength and resilience of Iraqi women and mothers. I also hope that those with Jill have come to know her -- that they recognise what a wonderful person she is and realise that they can show the world that they are merciful to an innocent woman by returning her safely home to us."

Mr Kember and his two Canadian colleagues from the Christian Peacemaker Teams organisation were found tied up in a house in western Baghdad, although their captors had fled and no shots were fired. An American abducted with them, Tom Fox, was killed three weeks ago and his battered body dumped near a railway line.

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