NEW DELHI: Intelligence agencies have warned that a Delhi-Kabul flight may be hijacked by terrorists.The input is quite specific and also mentions that an Air India flight could be targeted.A high alert has been sounded after the intelligence input. IGI airport has been alerted and stringent checks of even the staff members have been instructed.The authorities have put in place multi-level checking and have issued strictures to ensure they are followed judiciously.An additional ladder-point check has also been made compulsory. The security checks are expected to take more time now.Sources said that the ground staff has been asked to thoroughly check all cabin baggage once the passengers boarded.Commandos will also patrol the adjoining areas of the airport with LMG-mounted vehicles.The number of flight marshals have also been increased and cabin crew have been asked to look out for problem elements.Earlier in 1999, terrorists had hijacked IC 814 to Kandahar and intelligence alert says that this bid could be similarly executed.The alert comes in the wake of Obama's visit to India on the Republic Day which has heightened the threat perception in the city.