Aid agencies on Saturday plastered the Afghan capital with posters seeking information about a kidnapped Italian relief worker.

Clementina Cantoni, 32, who was working for CARE International (search) on a project helping Afghan widows and their families, was dragged from her car by four men in the center of the capital, Kabul, on Monday.

Since then, hundreds of police have manned roadblocks and searched poor neighborhoods where they suspect she may be held captive.

"Please help Clementina. She has been taken. For three years she served 10,000 widows and 50,000 war orphans in Afghanistan. If you have any information, please call," the posters said.

President Hamid Karzai (search) also called for her release.

"Whoever has kidnapped her is the enemy of Afghanistan. We know who kidnapped her and we know why he has kidnapped her," he told reporters. "We want her to be released securely and healthy."

Authorities have said they suspect the kidnapping was the work of the same criminal gang accused of abducting three U.N. workers last year. They were released a month later.

Karzai's call came after a bewildering series of demands and claims by a man named Temur Shah that he had kidnapped the aid worker, who has been in Afghanistan (search) since 2002.

Shah told independent Tolo TV early in the week he would slay her by Wednesday if the government didn't meet his demands for more Islamic schools, more aid for opium farmers and the removal of a liberal radio show from the airwaves.

Shah later extended the deadline and on Friday, reports quoted him as saying he had killed her because the government did meet the demands. But he later told The Associated Press by telephone that he had brought a doctor to treat Cantoni and that she was OK.

Presidential spokesman Jawed Ludin told Tolo TV that the government was "working very seriously" to secure the woman's release.