Travellers from 14 nations including Pakistan, Afghanistan, Nigeria and Saudi Arabia flying into the United States will face additional screening starting on Monday. <br/>US officials have said that the heightened security procedures include full body pat downs before boarding, checking of carry on baggage, and random checks on US bound flights. <br/>US Transportation Security Administration, in a statement released on Sunday, says every individual flying into the US from anywhere in the world travelling from or through nations that are state sponsors of terrorism or other countries of interest will be required to go through enhanced screening. <br/>Other marked countries include Algeria, Lebanon, Iraq, Yemen, Somalia, Cuba, Iran, Sudan and Syria. The new rules will apply to anyone stopping in these 14 nations and passport holders of these nations.<br/>However, American citizens and foreigners not flying through these nations will not be subject to the enhanced screening, Obama administration officials said.<br/>Security was tightened in the US airports following an attempt by a 23-year-old Nigerian student to detonate an explosive aboard the Delta Flight from Nigeria that landed in Detroit on Christmas day.<br/>