The agency's "red alert" came amid separate reports that the leader of the terrorist group was a Christian convert. The man, known so far only by his Jihadi fighting name of Omar or Umayr was Kenyan national, born to Christians from Nairobi. He converted to Islam and was also a former member of Kenya's special forces and is understood to have left for Somalia in 2005, where he joined the Kamboni militant Islamist group, which joined with al-Shabaab.
Meanwhile, Lewthwaite, 29, is wanted by Kenya on charges of possession of explosives and conspiracy to commit a felony dating back to December 2011.
She is also believed to use the alias Natalie Webb and is the widow of Germaine Lindsay, one of the London tube bombers of July 2005.
Interpol said it had received the request from Kenyan authorities on Wednesday and had issued a first alert to its 190 member countries immediately. The agency issued images, including one of Lewthwaite in a headscarf, another with her hair uncovered.
British police have cited Lewthwaite as a possible suspect in Saturday's attack on a Nairobi shopping mall by Islamists from Somalia's al Shabaab movement.
The four-day mall siege, which ended on Tuesday, killed 61 civilians, six members of the security forces, and five militants, according to officials. Yesterday the Foreign Office revised the figure on the number of Britons killed from six to five.
Some witnesses said women were among the attackers, but al Shabaab denied on its Twitter feed using "our sisters" in its military operations.
Kenyan security officials, joined by experts from the United States, Britain and Israel, continued to scour the Westgate mall for clues from the well-planned attack, as the army combed the building for explosives.
An Interpol spokeswoman clarified that the notice was not an international warrant for Lewthwaite's arrest.
"Through the Interpol Red Notice, Kenyan authorities have ensured that all 190 member countries are aware of the danger posed by this woman, not just across the region but also worldwide," Interpol Secretary Ronald Noble said in a statement.
In Washington, officials in the investigation said there was no hard evidence implicating Lewthwaite or any other British or U.S. nationals in the attack.
Lewthwaite is wanted by Kenya in connection with a bombing plot targeting luxury hotels and restaurants that involved another Briton, Londoner Jermaine Grant.
She is believed to be a member of al-Shabaab, and has been linked to a plot to bomb hotels and restaurants in tourist areas on Kenya's coast. In March, it was reported that she had been living in a house in Mombasa.
When the house was later raided by police it was found to contain an "arsenal of bomb-making materials".
Grant, who police said has suspected ties to al Shabaab, was arrested in a December 2011 raid along with a female accomplice, Warda Breik, who police said was his wife. Police said a third suspect, believed to be Lewthwaite, escaped in that raid.
l SHOPPING centres in Britain should not become "prisons" as new protection measures are considered amid fears of copycat terror attacks, according to The British Council of Shopping Centres.