US Investigating Possible Mail Bomb Terror Plot

"Authorities on three continents were investigating on Friday whether suspicious packages shipped from Yemen to the United States aboard cargo planes could be part of a terrorist plot.

Yemen is home to the al-Qaida branch that tried to bomb a U.S.-bound airliner on Christmas. No explosives have been found.

Intelligence and law enforcement officials discovered suspicious packages in the United Kingdom and Dubai late Thursday night, prompting national security officials to alert President Barack Obama to a ""potential terrorist threat,"" the White House said.

The UK package, discovered aboard a plane in East Midlands, about two hours north of London, contained a toner cartridge with wires and powder. It was found during routine screening of cargo in the United Kingdom, prompting authorities to scour three planes and a truck in the United States on Friday, U.S. officials said.

""The president directed U.S. intelligence and law enforcement agencies, and the Department of Homeland Security, to take steps to ensure the safety and security of the American people, and to determine whether these threats are a part of any additional terrorist plotting,"" the White House said in a statement.

Searches also were conducted in Philadelphia, Newark, N.J., and New York City. The packages were being sent via UPS.";_ylt=AlOk6PVAJb5YeBGsz2HhCS.s0NUE;_ylu=X3oDMTNsZG03bTc1BGFzc2V0A2FwLzIwMTAxMDI5L2FpcnBvcnRzX3N1c3BpY2lvdXNfcGFja2FnZXMEY2NvZGUDbW9zdHBvcHVsYXIEY3BvcwMxBHBvcwMxBHB0A2hvbWVfY29rZQRzZWMDeW5fdG9wX3N