Two hikers suffered serious head injuries and multiple fractures after falling 10 metres off the top of a cliff on Lantau yesterday. The men, both aged 22, were airlifted by a Government Flying Service helicopter from Nei Lak Shan near Ngong Ping. They and two other men set off from Tung Chung to Po Lin Monastery. They had reached a cliff at Nei Lak Shan at about 1pm when one of the victims slipped off. 'When another victim went to rescue him, both men accidentally rolled down further to the bottom of the cliff,' a police spokeswoman said. Police and fire officers were called in when their friends heard their screams and called for emergency help. The helicopter with a nurse on board was then sent. GFS operations manager Calvin Shum Chi-wan said: 'One of the injured victims had an open wound on his head and suffered multiple fractures, cuts and scratches. He was unconscious. 'The other man was in a semi-conscious state suffering head injuries and multiple fractures.' The unconscious man was first airlifted to Tuen Mun Hospital, according to Mr Shum. At about 2.20pm, the second victim was picked up and taken by helicopter to the same hospital. Both were in critical condition last night. Mr Shum said the operation took 90 minutes. Their friends were unhurt and walked down the hill.