BAGHDAD, Iraq – Margaret Hassan, an aid worker kidnapped after decades of helping Iraqis, was believed murdered, her family and aid officials said yesterday after Al Jazeera TV reported it received a video showing a hooded insurgent shooting a blindfolded woman in the head.

Hassan was believed to be the first foreign female hostage killed in Iraq’s wave of kidnappings. More than 170 foreigners have been abducted this year, and at least 34 killed. One woman – a Polish-Iraqi citizen – remains captive.

Hassan’s family in London said the longtime director of CARE in Iraq was likely the victim, and the British foreign secretary, Jack Straw, said analysis of the video showed Hassan had “probably been murdered, although we cannot conclude this with complete certainty.”

CARE said it was in mourning for the 59-year-old Briton, a veteran humanitarian worker known around the Mideast for her concern for Iraqis – particularly during the years of U.N. sanctions, whose effects on children she vocally denounced.

“To kidnap and kill anyone is inexcusable,” Mr. Straw said. “But it is repugnant to commit such a crime against a woman who has spent most of her life working for the good of the people of Iraq.”

In an emotional appeal on Al Jazeera, Hassan’s Iraqi husband, Tahseen Ali Hassan, said he had heard of the video but did not know whether it was authentic.

“I appeal to those who took my wife [to tell me] what they did with her. …I want my wife, dead or alive. If she is dead, please let me know of her whereabouts so I can bury her in peace,” he said, his voice choked with tears.

The video shows a hooded insurgent firing a pistol into the head of a blindfolded woman wearing an orange jumpsuit, said Al Jazeera spokesman Jihad Ballout. The station received the tape a few days ago but had not been sure of its authenticity until recently, he said.

“We invited British diplomatic officials to come and view it,” he said. “It’s now likely that the image depicts Mrs. Hassan.”

Mr. Ballout said the station would not air the video and would not broadcast any acts of killing, outside war. Al Jazeera has been under pressure not to show videos of kidnapped foreigners.

Hassan was abducted in Baghdad on October 19 on her way to work, the most prominent of more than 170 foreigners kidnapped in Iraq this year. Her captors issued a series of videos showing her weeping and pleading for Britons to act to save her. In one video, she fainted and a bucket of water was thrown on her to revive her.

In one video, she begged Prime Minister Blair to withdraw troops from Iraq and calling for the release of female Iraqi prisoners.

On Sunday, American Marines found the mutilated body of what they believe was a Western woman on a street in a Fallujah during the American assault on the insurgent stronghold. The American command said the body had not been identified as of last night.

Besides Hassan, the only Western woman known to be held was Teresa Borcz Khalifa, 54, a Polish-born longtime resident of Iraq seized last month.

A Blair spokesman said the prime minister “sends his sympathy to the family of Margaret Hassan and shares their abhorrence at the cruel treatment of someone who devoted so many years of their life to helping the people of Iraq.”

CARE said it was “with profound sadness” that it learned of the video. “The whole of CARE is in mourning,” said the group, which closed its Iraq operations after the kidnapping.

Hassan’s four brothers and sisters also said they believe she is dead, although their statement did not mention the video.

“Our hearts are broken,” they said in a statement released by the British Foreign Office. “We have kept hoping for as long as we could, but we now have to accept that Margaret has probably gone and at last her suffering has ended.”

The family said, “Those who are guilty of this atrocious act, and those who support them, have no excuses.”

Al Jazeera reported on November 2 that Hassan’s captors threatened to turn her over to followers of Jordanian insurgent Abu Musab al-Zarqawi.

Three days later, Mr. al-Zarqawi’s Al Qaeda in Iraq group called for Hassan’s release and promised to free her if she fell into their hands, according to a message posted on a Web site known for publishing messages from Islamic terrorist groups.

Mr. al-Zarqawi and his men have been blamed for numerous deadly car bombings and the slayings of foreign hostages, including three Americans and a Briton. Born in Ireland, Hassan also held British and Iraqi citizenship. She met her husband at college and moved with him to Baghdad.

Also last night, American and Iraqi troops recaptured police stations and secured bridges in the northern city of Mosul yesterday in an offensive aimed at pushing out fighters supporting the insurgent stronghold of Fallujah.

Troops met “very little resistance” in securing several of the dozen or so police stations that had been captured by insurgents, the American military command said. Nineveh province’s deputy governor said rebels blew up the Zuhour police station ahead of the American advance, but the American military denied any stations were destroyed.

Loud explosions and gunfire could be heard as American warplanes and helicopters circled over Mosul, Iraq’s third-largest city with more than 1 million residents.

Mortar shells hit two areas near the main government building in the city center, killing three civilians and wounding 25, hospital officials said. One American soldier was wounded when a car bomb exploded near an American convoy in western Mosul, the military said.

The American-led offensive is aimed at seizing control of the city 225 miles north of Baghdad, where gunmen stormed police stations, bridges, and political offices last week. The city’s police force was overwhelmed and in many places failed even to put up a fight. Some officers also allegedly cooperated with insurgents.

The operation was launched after American and Iraqi reinforcements were rushed to Mosul.