Counterterrorism officials have begun a search for more suspicious cargo, after two packages containing explosives were intercepted in Britain and Dubai on Friday. The two packages were disguised as printer toner cartridge shipments, and were sent from Yemen and addressed to Jewish religious centers in Chicago. No additional explosives were found by Friday night, and cargo planes were moved to secure areas of the Philadelphia and Newark airports. Rep. Jane Harman (D-CA), who is on the House Homeland Security Committee, said the seized packages contained the same chemical explosive as the one found in the bomb sewn into the underwear of the Nigerian man who tried to blow up an airliner on Christmas Day. Intelligence officials in Saudi Arabia tipped off the U.S. to the plot to ship explosives from Yemen. Despite the increased role of Yemenis in recent terror plots, U.S. officials stressed that Yemen has been cooperating with terrorism investigations.