U.S. transport authorities have ordered enhanced screening procedures for U.S.-bound air passengers traveling through "state sponsors of terrorism or other countries of interest", CNN said on Monday.

The TV channel's website quoted an unauthorized senior government official as saying a total of 14 countries were included into the Transportation Security Administration's "countries of interest" list. Cuba, Sudan, Syria and Iran are listed as those that sponsor terror. The other 10 countries of interest are Afghanistan, Algeria, Iraq, Lebanon, Libya, Nigeria, Pakistan, Saudi Arabia, Somalia and Yemen.

The TSA was quoted as saying in a statement the measure was intended to ensure "effective aviation security" beyond the U.S. borders.

Air security has been tightened in the U.S. following a failed Christmas Day bombing attempt over Detroit.

A 23-year-old Nigerian national, Umar Farouk Abdulmutallab, a passenger on board an A330 passenger jet bound from Amsterdam to Detroit on December 25, tried to blow up the plane that was carrying some 300 people. He was detained and charged with attempted terrorist attack.

U.S. President Barack Obama said on Saturday the bomb suspect was apparently trained by a Yemen-based Al Qaeda offshoot.

Abdulmutallab also allegedly claimed after his arrest that he acted on instructions from Al Qaeda. U.S. security officials have confirmed that his name was on the U.S. list of terrorist suspects.

Al Qaeda said in a statement posted on radical Islamist websites the attack carried out by its "brother" was retaliation for alleged U.S. strikes on Yemeni soil in December.

MOSCOW, January 4 (RIA Novosti)