Authorities investigate UPS containers in the cargo area of East Midlands Airport, near Nottingham central England on Thursday. ((David Jones/Associated Press))

A Yemen-based al-Qaeda group is claiming responsibility for the cargo mail bomb plot uncovered late last week in a release that appeared on Islamist websites.

A week after authorities intercepted packages in Dubai and England that were bound for the United States, al-Qaeda in the Arabian Peninsula issued a message Friday saying it will continue to strike American interests.

Both mail bombs were wired to detonators that used cellphone technology and were hidden in the toner cartridges of computer printers, but were intercepted before causing any damage.

The group also claimed responsibility for the downing of a United Parcel Service cargo plane in Dubai in September.

A U.S. official said that authorities have found no evidence that the crash of the Boeing 747-400 was caused by a bomb. Investigators still do not know what caused the fire that erupted on the plane's main cargo deck.

U.S. officials including President Barack Obama have said they believe it was the Yemen group that was behind last week's attempts.

The claim was posted on Islamist internet forums and translated by the private SITE Intelligence Group.