Insurgents kill Russian police officer -- media

MOSCOW, July 31 (Reuters) Insurgents in Russia's North Caucasus region killed a police officer and wounded three today in an attack on a police unit's bus, Russian media reported.

The attack occurred as the police escorted a goods truck through Ingushetia, a mainly Muslim republic next to the Chechnya region which is the scene of a long-running anti-Moscow insurgency.

''The attack was very sudden, the police did not even have time to open fire,'' Interfax news agency quoted a local Interior Ministry official as saying.

No immediate comment was available from officials on the reports.

Violence in Chechnya has spilled over into neighbouring republics in the North Caucasus, including Ingushetia, where insurgents with Islamist links launch attacks on government targets.

Attacks in Ingushetia have become more frequent in the past few weeks. On July 6, gunmen used grenade launchers to attack a Russian military base. Two weeks later, an adviser to Ingushetia's president was shot dead.

REUTERS RJ PM1200