The statement said the bombing in Islamabad was carried out to fulfill the promise of terror mastermind Osama bin Laden to exact revenge over the reprinting in Danish papers of a cartoon of Islam's Prophet Muhammad.
It said the bombing came in defense of the religion, the blood and the honor of Muslims, and warned that if Denmark fails to apologize for the cartoons, more attacks will follow and Monday's blast will "only be the first drop of rain."
The group said their attack is but a "warning to this infidel nation and whoever follows its example."
Denmark "published the insulting drawings of the messenger" and later "refused to apologize for publishing them, instead they repeated their act," it said.
The authenticity of the statement, which was posted on a website frequently used by Islamic militants, could not be independently verified. It was signed by an al Qaeda commander in Afghanistan, Mustafa Abu al-Yazeed, and dated Tuesday.
It said the bombing was carried out by an al Qaeda martyr whose last will and testament will soon be made public, and thanked Pakistani jihadists who allegedly helped prepare and execute the plot.
Denmark officials said earlier that they suspected al Qaeda was behind the Islamabad attack.
The terror network has threatened Denmark over the reprinting in Danish papers earlier this year of a cartoon that depicted Prophet Muhammad wearing a bomb-shaped turban.
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 European media.
The drawing showing Muhammad wearing the 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.
Renewed protests followed the reprinting, though not as large or widespread as those in 2006. In March, bin Laden warned in an audio recording posted on a militant Web site of a "severe" reaction against Europe over the cartoon's republishing.
Muslims widely see the cartoons as an insult and depicting the prophet as violent. Islamic law generally opposes any depiction of the prophet, even favorable, for fear it could lead to idolatry.
The Islamabad bombing has added to concerns that Pakistan's efforts to strike peace deals with militants along the Afghan border are failing to curb Islamic extremist violence.
Washington has also expressed concerns that the two-month-old Pakistani government's efforts to negotiate with some armed groups in the northwest could give al Qaeda and Taleban hard-liners time to regroup and intensify attacks in Afghanistan and elsewhere.
