Following the killing of Indian Ramankutty Maniyappan in Afghanistan, security has been tightened for the cast and crew of "Kabul Express", which is stationed in Kabul for the shooting.

Relatives and friends of Arshad Warsi and John Abraham, who play the two main protagonists, have been telephoning their homes to inquire about their safety.

However, the Afghan government has been taking additional measures to ensure protection for the whole unit.

According to Arshad Warsi's wife Maria Goretti, the unit is unlikely to get into any trouble because of director Kabir Khan, who is thoroughly well acquainted with the rough terrain of Afghanistan.

Khan, a reckoned documentary filmmaker in his own right, has shot a record number of documentaries in Afghanistan. According to Goretti, who was in Kabul for the first schedule of the film, the Afghan police were guarding the unit round-the-clock.

Very few artistes have ventured into Afghanistan in recent times. A few months ago singer Sonu Nigam went there for a show at the invitation of his Afghan friends. The show got a thumping response though the security measures sent his family worrying about his safety till he returned.

"Kabul Express" is a thriller and an anti-war film set post 9/11. It tells the story of a 48-hour car drive in Afghanistan, whose Taliban regime was ousted by the US after the terror attacks. Arshad Warsi plays a cinematographer and John Abraham a TV director.