Top officials of four federal agencies decided...

Top officials of four federal agencies decided Tuesday to continue searches of vehicles crossing the U.S.-Mexico border to look for clues in the kidnaping of a U.S. drug enforcement agent. The U.S. Customs Service, Immigration and Naturalization Service, Drug Enforcement Administration and Justice Department officials agreed to reevaluate their decision at the end of the week. For a fifth day along the border, U.S. Customs and immigration agents combed vehicles driven by Mexicans, causing delays of up to 2 1/2 hours at the San Ysidro crossing. Pedestrians had to wait as long as an hour to cross into the United States. Immigration and Customs officials said their searches have not yielded any leads into the disappearance of Enrique S. Camarena, the DEA agent abducted Feb. 7 in Guadalajara.