Two police officers are in hospital following an explosion in Russia`s North Caucasus republic of Chechnya, a law enforcement source said on Monday. The explosion occurred "during a reconnaissance operation carried out by special forces," the source said, adding that the officers had been hospitalized. The violence also continued overnight in neighboring Ingushetia when gunmen fired over 118 rounds from automatic weapons and grenade launchers at a police building in Nazran, the republic`s largest city. "The building was badly damaged but no one was hurt," a police source said. Russia`s mainly Muslim North Caucasus regions have seen a rise in violence in recent months. Attacks on police, officials and troops have been reported almost daily in Ingushetia and Daghestan. A top police official died last week following an attack on his car in Nazran. A suicide bombing late last month left Ingush President Yunus Bek Yevkurov severely injured and killed three of his bodyguards. And in neighboring Daghestan the republic`s interior minister was assassinated earlier in June. The Kremlin announced a formal end to its 10-year counter-terrorism operation in the troubled region on April 16, but violence has continued in Chechnya and neighboring republics.