Responding to complaints from American and British officials, YouTube on Wednesday removed from its site some of the hundreds of videos featuring calls to jihad by Anwar al-Awlaki, an American-born cleric based in Yemen who has been blamed for radicalizing Muslims involved in a string of terrorist attacks.

On Tuesday, amid concerns that the cleric might have been linked to a thwarted plot to bomb cargo jets, prosecutors in Yemen charged Mr. Awlaki in absentia with inciting violence by sending Internet messages to a 19-year-old Yemeni man, who is on trial for murdering a French oil company worker last month, urging him to kill foreigners.

• Islam and terrorism

A Muslim woman who tried to kill a Labour MP by stabbing him in the stomach was jailed for life on Wednesday.

Roshonara Choudhry, a 21-year-old student, twice plunged a knife into former minister Stephen Timms when she went to meet him at his constituency office in east London on May 14 this year, shortly after the general election.

Judge Jeremy Cooke said Choudhry , reportedly after watching online sermons by Yemeni-US cleric Anwar al-Awlaki, would continue to be a danger to MPs for the foreseeable future and passed a life sentence with a minimum term of 15 years.

“You said you ruined the rest of your life. You said it was worth it. You said you wanted to be a martyr,” said Cooke, sitting at the Old Bailey…

In nearly a dozen recent terrorism cases in the United States, Britain and Canada, investigators discovered the suspects had something in common: a devotion to the message of Anwar al-Awlaki, an eloquent Muslim cleric who has turned the Web into a tool for extremist indoctrination.

Maj. Nidal Malik Hasan, the Army psychiatrist charged with killing 13 people at Fort Hood, Tex., on Nov. 5, is only the latest suspect accused of perpetrating or plotting violence to be linked to the cleric.