The scene following the blast near the Danish embassy
An internet posting purportedly by al-Qaeda in Afghanistan says it carried out Monday's car bomb attack on the Danish embassy in Pakistan.
At least six people were killed and 30 injured in the attack in the Pakistani capital, Islamabad.
The statement said it was revenge for the reprinting of a "blasphemous" cartoon of the Prophet Mohammed in Danish newspapers in February.
The cartoons, deemed offensive to Islam, led to worldwide protests.
The authenticity of the statement, which was posted on a website used by Islamic militants, could not be independently verified.
The statement, signed by one Mustafa Abu al-Yazid, said that if Denmark did not apologise for the cartoons, more attacks would follow.
Meanwhile, Denmark has sent a team to Islamabad to investigate the attack.
They have handed over the embassy's surveillance footage to Pakistani investigators.
The blast damaged the embassy and nearby vehicles
It shows a man driving a car at high speed in front of the embassy before it exploded.
The car, a Suzuki, carried a Danish embassy diplomatic registration plate to avoid security.
The BBC's M Ilyas Khan in Pakistan says that diplomatic missions in Islamabad do not use Suzukis and security guards have been criticised for not stopping and checking the vehicle.
Newspaper reports quoting unnamed police and interior ministry sources say a number of arrests have been made in connection with the attack.
The al-Qaeda statement said that the bombing was a "warning to this infidel nation and whoever follows its example".
It warned that if Denmark failed to apologise for the cartoons, more attacks would follow and Monday's blast would "only be the first drop of rain".
The statement said that Denmark "published the insulting drawings" and later "refused to apologize for publishing them, instead they repeated their act".
It also said the bombing was carried out by an al-Qaeda martyr whose last will and testament would soon be made public. It thanked Pakistani jihadists for helping execute the plot.
Danish PM Anders Fogh Rasmussen has called the act "cowardly" and said it would not change Danish policies.
Investigators initially said it was not clear who carried out the attack, as Pakistan's main militant group had recently declared a ceasefire.
Correspondents say that just a few weeks before the attack, al-Qaeda threatened Denmark over the Prophet Mohammed caricatures.
Monday's bombing followed a relative lull in militant attacks since a new government came to power after February elections pledging to negotiate an end to violence.
Pakistan's top Taleban leader, Baitullah Mehsud, is in peace talks with the authorities in an attempt to end fighting in the country's north-west.
Other militant factions - accused of being involved in similar attacks in the past - have also recently engaged in talks with the government.