Five gunmen were killed at the Chechen-Ingushetian border on Saturday, a source at theNational Antiterrorism Committee told Russian Itar-Tass news agency Saturday.A group of 15 gunmen was discovered in the area of the settlement of Dattykh. Five members of the group werekilled when they attempted to break through the cordon.None of the law-enforcement personnel was hurt.Earlier today, a military helicopter crashed in the Russian republic of Chechnya on early Saturday, killing three of four people on board, Russian News Agency (RIA Novosti) reported.The incident is tentatively blamed on heavy fog in the vicinity of the Khankala military base and not terrorist activity in the once-volatile North Caucasus republic, the official said on condition of anonymity.Only crew members were on board of the Mi-8 helicopter at the time of the crash, the unnamed official said, adding that the surviving pilot was hospitalized. A check was ongoing