The militant group al-Qaeda's Yemen-based wing has claimed it sent two parcel bombs on cargo planes bound for the United States last week.
In messages on Islamist websites, al-Qaeda in the Arabian Peninsula the group also said it was responsible for bringing down an American cargo plane in Dubai in September.
The group has vowed to continue to target the US and its allies.
The parcel bombs were made safe after being discovered on flights from Yemen which landed in Britain and Dubai, the BBC reports.
In Washington, a US counter-terrorism told Reuters there are strong indications the group was behind the disrupted cargo plant plot but could not confirm that AQAP was behind the 3 September crash of the UPS aircraft.