A video of a senior charity worker who has been kidnapped in Baghdad has been broadcast on al-Jazeera TV station.
Margaret Hassan was shown on al-Jazeera television
Margaret Hassan has dual Iraqi and British nationality and is married to an Iraqi.
She has lived in the country for 30 years and was abducted by an unnamed group on her way to work as head of Care International's work in Iraq.
Prime Minister Tony Blair condemned the kidnapping and said Mrs Hassan had spent years helping Iraqi people.
"I think it shows you the type of people we are up against, that they are prepared to kidnap somebody like this," he said.
Mrs Hassan, who was born in Dublin, was kidnapped at around 0730 (0430 GMT) on Tuesday.
In an interview with al-Jazeera her husband Tahseen
Ali Hassan said his wife was abducted near the charity's office.
He said two cars had intercepted her, attacked the driver and taken the car to an unknown destination.
His wife had not received threats, and it was still not known who had taken her, he told the Arabic station.
Mrs Hassan looked distressed in the video and had her hands tied behind her back.
According to al-Jazeera an Iraqi armed group said it had captured Mrs Hassan, but did not identify itself or give demands.
Care International UK's chief executive Geoffrey Dennis said: "We are not aware of the reasons why [she was taken]. Obviously we are doing the best we can locally to try to secure her and get her back again."
Mrs Hassan is an Irish citizen by birth.
The Department of Foreign Affairs in Ireland said it had been in touch with the UK Foreign Office, Mrs Hassan's family and Care International to gather information on her abduction.
BBC correspondent in Baghdad Claire Marshall said this latest incident showed kidnappers were getting increasingly confident.
She said: "It used to be people travelling between towns, a lot of truck drivers [were taken], now it seems the kidnappers have got more and more audacious.
"They are now snatching people literally just as they leave their homes and their work."
Pictures of Mrs Hassan's passport, credit and identity cards were also broadcast on television.
Foreign Secretary Jack Straw said he was "very concerned" adding: "Our thoughts and prayers go out to her, her family and her colleagues".
Defence Secretary Geoff Hoon described it as a "disturbing development" which "just demonstrates the depths to which these terrorists will go".
Care International is one of the largest independent global relief and development organisations in the world.
The charity operates in more than 72 countries in Asia, Africa, Latin America, the Middle East and eastern Europe.
In a statement about Mrs Hassan it said: "She has been providing humanitarian relief to the people of Iraq in a professional career spanning more than 25 years."
Fluent in Arabic
British journalist Robert Fisk got to know Mrs Hassan after readers of the Independent newspaper raised money for leukaemia medicines to be taken to Iraq in 1998.
In an interview with the Irish TV network RTE on Tuesday Mr Fisk said Mrs Hassan had done an "extraordinary job" of taking charge of distributing the drugs.
"She managed to browbeat the authorities, the UN and the Americans to get these medicines into Iraq. She is an extraordinarily energetic woman," he said.
Several documents belonging to Mrs Hassan were shown on al-Jazeera
The Baghdad correspondent said Hassan spoke fluent Arabic with an Iraqi accent, and was opposed to UN sanctions against Iraq.
The latest kidnapping comes less than two weeks after British contractor Ken Bigley, 62, was beheaded.
In September two female Italian aid workers were freed after being held hostage in Iraq for three weeks.
Simona Pari and Simona Torretta were seized in their Baghdad office.
Kidnappings are a daily event in Iraq, with most victims being Iraqis themselves, who are usually released in return for a ransom payment.