The man suspected of carrying out weekend bombings in Sweden said in a purported will that he was fulfilling a threat by Al Qaeda in Iraq to attack Sweden, the SITE monitoring group said on Monday.
"The Islamic state of Iraq has fulfilled what it promised you," said Taymour Abdel Wahab in the will posted by a jihadist on the Shumukh al-Islam website, according to the US-based group.
The Swedish capital was hit by twin explosions on Saturday — a suspected suicide attack and separate blast — targeting Christmas shoppers in a busy pedestrian area of the city.
A man investigators suspect may have been the bomber was killed while the other explosion nearby injured two people.
Shumukh al-Islam named Taymour Abdel Wahab as the man responsible for the blasts, although Sweden's intelligence agency Saepo has refused to comment on the claim.
The late chief of the self-proclaimed Islamic state of Iraq, Abu Omar al-Baghdadi, had called in an audio message in September 2007 for reprisals in Sweden for the cartoons of Islam's Prophet Mohammed by Swedish cartoonist Lars Vilks.
Baghdadi also offered cash for killing the cartoonist and named Swedish companies like Ericsson, Ikea and Volvo, as potential targets to harm Sweden's economy.
British media reported on Monday that Wahab had studied at the University of Bedfordshire in Luton, around 30 miles (50 kilometres) north of London, and had been living in the town in 2010.
His wife and children were reportedly still living in Luton, the Daily Mail and the Daily Telegraph reported.