DUBAI, DECEMBER 26 A London-based Arab magazine said on Friday that Al Qaeda leader Osama bin Laden has vowed to launch a ‘‘back-breaking attack’’ on the US by February, confirming an earlier message by the militant network. The weekly al-Majalla said it received an e-mail from Abu Mohammed al-Ablaj, a little known Al Qaeda member, saying bin Laden would release a video tape in which he affirms his group’s determination to fight the US.

‘‘A messenger of bin Laden informed him (Ablaj) that the Al Qaeda leader will appear on a televised tape after the execution of an operation which bin Laden described as back-breaking and which would change the order of things,’’ al-Majalla said in a report in its latest edition.

‘‘They (Americans) should prepare...their coffins, hospitals and graves. The coming days will be full of surprises and great events which will make them a historic example,’’ the magazine quoted Ablaj as saying. The report came after US officials ordered their colour-coded alert system raised to orange, the second highest level, citing possible year-end attacks.

Air France cancelled Christmas flights to Los Angeles on Wednesday after US officials relayed information that extremist groups were planning ‘‘near-term simultaneous attacks that would rival September 11’’.

In the e-mail, which could not be authenticated, Ablaj echoed his previous statement carried by al-Majalla in November saying the attack would take place before a Muslim feast which is celebrated on the last days of January or the first days of February.