Interpol issued a worldwide "red notice" alert Thursday on behalf of Kenya for the arrest of a British national known as the "white widow."

Samantha Lewthwaite, 29, a Muslim convert, is wanted by Kenya on two-year-old charges of possession of explosives and conspiracy to commit a felony, the international crime agency said in a news release. She is also wanted for alleged possession of a fraudulent South African passport.

The notice did not mention this week's attack by Islamist militants on an upscale Nairobi shopping mall that killed at least 67 people, including 18 foreigners, and injured another 175 people.

Lewthwaite, who may be using the alias "Natalie Webb," was married to suicide bomber Germaine Lindsay, also known as Abdullah Shaheed Jamal. He was one of the four suicide bombers who detonated explosives in London's subway system on July 7, 2005, which killed 52 people.

A "red notice" is circulated to police agencies in 190 counties, Interpol Secretary-General Ronald Noble said. A member country who spots Lewthwaite is being asked to place her under provisional arrest and extradite her to the requesting country.

Despite the lack of hard evidence, some members of the British media tried to link Lewthwaite to the shopping mall attack, particularly after Kenya's foreign minister said that a British woman had been involved.

The Independent newspaper said that survivors of the attack on the mall recall seeing a female acting in a leadership role and issuing orders during the assault. But the newspaper also cited security officials as saying there was no evidence Lewthwaite was involved and they also questioned her combat experience.

In addition, Kenyan President Uhuru Kenyatta said in an address Wednesday night night that "intelligence reports" had "suggested" that a British woman and two or three American citizens may have been involved in the attack. "We cannot confirm the details at present, but forensic experts are working to ascertain the nationalities of the terrorists."

The British Foreign Ministry confirmed on Thursday that five British nationals were killed in the mall attack. The British government had previously announced six British victims.

Al-Shabab, the Somali Islamist extremist group that took responsibility for the attack, said Wednesday that foreigners were a "legitimate target" and confirmed witness accounts that gunmen separated Muslims from other people and let the Muslims go free. The others were gunned down or taken hostage.

"The Mujahideen carried out a meticulous vetting process at the mall and have taken every possible precaution to separate the Muslims from the Kuffar (disbelievers) before carrying out their attack," the group said in an e-mail exchange with the Associated Press.

FBI agents have joined international experts at the crime scene. Working near bodies crushed by rubble in the bullet-scarred Westgate mall, FBI agents began fingerprint, DNA and ballistic analysis Wednesday to help determine the identities and nationalities of victims and al-Shabab gunmen who attacked the shopping center.

The mall attack was the deadliest terrorist attack in Kenya since the 1998 al-Qaeda truck bombing of the U.S. Embassy in Nairobi, which killed more than 200 people.

Lewthwaite is a mercurial figure who originally criticized her late husband for taking part in the transit attacks, but later apparently embraced the militants' cause.

She told The Sun newspaper in 2005 that her husband had fallen under the influence of radical mosques.

"How these people could have turned him and poisoned his mind is dreadful," the newspaper quoted her as saying. "He was an innocent, naive and simple man. I suppose he must have been an ideal candidate.

"He was so angry when he saw Muslim civilians being killed on the streets of Iraq, Bosnia, Palestine and Israel — and always said it was the innocent who suffered."

Britain's Evening Standard newspaper reported Thursday evening that Lewthwaite for a time allegedly worked in a South African halal pie factory as a computer technician.

The newspaper spoke to the pie factory's former owner, who did not want to be identified. The owner said the woman she knew as Natalie Faye Webb — one of several false identifies she apparently used during four years in South Africa — was "a quiet woman who kept to herself."

The newspaper said that "Webb" apparently ran up several thousands of dollars in debt on bank loans and credit cards. Consumer records indicate that Lewthwaite/Webb was last in South Africa in May of last year, the Standard said.

The Sunday Times of South Arica quotes an unidentified government official as saying she apparently had assumed the stolen identification of Webb and had applied for and gotten a South African passport and supporting documents.

Leinwand Leger reported from Washington, D.C. Contributing: The Associated Press