A young Arab man who tried to enter the Prime Minister's Office in Jerusalem on Sunday was detained for questioning after some "suspicious substance" was found in his shoes, in the second bomb scare at the office in the last week, police said. Police sappers took the shoes and carried out a controlled explosion outside the building, setting off four large booms. The shoes were determined to be explosives-free. The premier and his Cabinet ministers were in the building at the time, reviewing the UN cease-fire deal. Last week, the office was briefly evacuated after a similar bomb scare.