LAHORE - Pakistani police said on Friday they had arrested a Muslim cleric accused of leading a mob trying to kill a Christian couple for allegedly desecrating the Koran.Police rescued the Christians from the crowd near the eastern city of Lahore on Thursday, a relatively unusual intervention in a country where those accused of blasphemy are sometimes lynched on the spot.Police officer Sohail Zaffar Chattha said the cleric leading the mob demanded that police arrest the couple and charge them with blasphemy against Islam."I told him I would not register a case because no blasphemy has been committed," Chattha said in a telephone interview."But I have registered a case against the cleric and 400 others for inciting violence and endangering the lives of the couple."About 500 people in Sadar Farooqabad town attacked Owais Masih and his wife after a neighbor complained that they were sleeping on a plastic sheet with verses from the Koran written on it.Police rescued the couple as the mob began to beat them. The couple were later taken into protective custody and moved to an undisclosed location.