Updated

A statement attributed to Al Qaeda on Thursday claimed responsibility for this week's deadly bombing at the Danish Embassy and threatened more attacks on countries where cartoons of the Prophet Muhammad are published.

The statement, signed by an Al Qaeda commander in Afghanistan, also lauded Pakistani jihadists for assisting in the Monday suicide car bombing, which came as Pakistan seeks controversial peace deals with militants in its border regions.

The blast killed six, including one Danish citizen, and caused widespread destruction in the neighborhood. A Danish official said Thursday that Denmark had shared with Pakistan a video of the attack that showed the vehicle arriving outside the embassy and exploding.

Danish officials already have said Al Qaeda is the top suspect, and the Internet statement appeared to strengthen that assessment.

• Click here for photos.

The post was dated Tuesday and signed by Mustafa Abu al-Yazeed. It said the attack was designed to fulfill Usama bin Laden's promise to exact revenge for the reprinting in Danish newspapers of a cartoon of Islam's prophet wearing a bomb-shaped turban.

And it warned that if Denmark fails to apologize for the cartoons, more attacks will follow and that Monday's blast will "only be the first drop of rain."

The attack is but a "warning to this infidel nation and whoever follows its example," it said. Denmark "published the insulting drawings" and later "refused to apologize for publishing them, instead they repeated their act," the posting said.

The statement's authenticity could not be independently verified, though it was posted on a site frequently used by Islamic militants.

Ben Venzke of IntelCenter, a U.S. group which monitors Al Qaeda messages, said prime targets for al-Yazeed's threat would be embassies and diplomatic personnel in Pakistan from countries where cartoons were published. Venzke said Norway, the U.S. and all European Union member countries, including Denmark, were most at risk.

Islamic law generally opposes any depiction of the prophet, even favorable, for fear it could lead to idolatry. In early 2006, a dozen Muhammad cartoons, originally published in a Danish newspaper, triggered fiery protests in Muslim countries when they were reprinted by a range of Western media, mostly in Europe.

The drawing of Muhammad in a bomb-shaped turban appeared again in Danish newspapers Feb. 13, after Danish police said they foiled an alleged plot to murder the cartoonist who drew it.

Monday's attack was the deadliest strike against Denmark since the cartoons' publication.

Al Qaeda militants are believed to have found safe havens and linked forces with pro-Taliban elements in Pakistani tribal regions bordering Afghanistan.

Pakistan's newly elected government is in peace talks with militants to try to curb Islamic extremist violence in its territory.

The U.S. is worried the deals will give militants time to regroup, but Pakistan Foreign Ministry spokesman Mohammed Sadiq defended the peace talks Thursday, saying it was not negotiating with "terrorists."

A 10-member Danish crisis management team is in Pakistan to help probe the bombing and assess security for the Danish diplomatic mission in the capital.

Spokeswoman Louise Brincker said the Danes have shared a video from a closed-circuit camera with Pakistani investigators that shows the car arriving outside the embassy and exploding.

She said it is not possible to see the license plates because of the camera angle. Danish Foreign Minister Per Stig Moeller said Wednesday the video also doesn't show who was in the car.

Pakistani officials have said the car was stolen and equipped with fake diplomatic plates to help gain access to the street, which is not barred to the general public but has high security.