A group of Islamic militants have targeted the Channel Tunnel between England and France during the holiday season, according to a British newspaper.

The CIA warned the French foreign intelligence service, DGSE, about the alleged plan in a Dec. 19 report, the Observer says.

The plan was put together in Pakistan and is being directed from there, French sources told the newspaper. The plot involves militants believed to be Western Europeans, possibly Britons of Pakistani descent.

The Channel Tunnel is a 50-kilometre rail tunnel that connects England and France. Millions of passengers are transported through it each year. 

The paper quotes the DGSE as saying the levels of "chatter" between militants has not been so high since 2001.

Militants with links to al-Qaeda are also plotting a wave of attacks on an unidentified European country, according to the Observer.

The plot is apparently being planned and run from Syria and Iraq. It said the threat was greatest between this past September and April.

British officials warned Friday that there is a high threat of an attempted  attack over the Christmas and New Year period, although they said they had no intelligence of any specific plots.

With files from the Assocatied Press