A British aid worker, believed to be in his 70s, has been kidnapped in Iraq along with three other Westerners.
Norman Kember was kidnapped with three other Westerners
It is understood Professor Norman Kember was snatched in Baghdad along with two Canadians and an American. The Foreign Office is investigating.
Professor Kember, from north-west London, was said to be representing a number of humanitarian aid groups.
His wife Pat, at home in Pinner, said: "People are being very, very good to me and I'm being supported."
A Canadian official confirmed that two Canadian nationals were seized, but did not name them. The fourth hostage is said to be American but there has been no confirmation.
It is one of the largest groups of Western hostages to have been taken in Iraq.
So far few details have emerged of how they were abducted or who may have been behind it.
The BBC's Caroline Hawley, in Baghdad, said it was understood they were snatched on Saturday, from a potentially dangerous district of western Baghdad.
She said it appeared the group may have been in the area with "pretty minimal" security.
Most Western aid agencies pulled their workers out of Iraq following the abduction of Margaret Hassan in 2004, with few now operating outside Baghdad's heavily-guarded Green Zone.
The Foreign Office confirmed Mr Kember's identity but gave no further details.
A spokesman said: "We will be in touch with the Iraqi authorities, and with the other countries involved, the Americans and the Canadians.
"We will be setting in motion an urgent investigation."
Special British embassy hostage teams are thought to be focusing on who seized the four and what their motives were.
'Lovely white hair'
An official at one of the peace groups where Mr Kember sometimes works said: "I didn't know he was in Iraq. If he went there he went very quietly.
"I've known him since the 1960s. He's a peacemaker. He's a person of great resources... he'll keep his sense of humour.
"He's not a foolhardy man, he'd know exactly what he was getting himself into."
He said Mr Kember, who had "lovely white hair", had been a professor at a teaching hospital in London.
He added: "He was incredibly active. He was against the war. He went on the big demonstration against it in London and felt very strongly about it.
"As far as I know, he went to Iraq as an individual, he didn't go as part of our group."
BBC correspondent Lee Carter, reporting from Toronto, said the kidnapping had been met with "a great deal of shock" in Canada.
The country had opposed the war in Iraq and was not among the US-led "coalition of the willing" which invaded Iraq and deposed Saddam Hussain.
He added: "There has been this feeling that Canadians and Canadian aid workers have been immune to this sort of kidnapping."
This is the first snatching of foreign civilians in Baghdad since the kidnapping of Guardian reporter Rory Carroll, who was held for 36 hours last month and later released unharmed.
It is estimated that over the past year and a half, at least 200 foreigners have been abducted in Iraq.
Two British civilians have been taken hostage and killed.
Margaret Hassan, an aid worker who had lived in Iraq for more than 30 years, was kidnapped in October 2004.
Her body has never been found, but she is believed to have been murdered.
Kenneth Bigley, a 62-year-old engineer, was kidnapped in September 2004 and beheaded.