One police officer was killed and six others wounded in a clash with militants in southern Chechnya on Wednesday, a police source in the Russian North Caucasus republic said on Thursday. "One police officer was killed and six others were wounded in a clash with members of an illegal armed group," a police officer said. "One militant, a resident of [the neighboring republic of] Daghestan, was killed in retaliatory fire." He said the skirmish, which broke out in a wood near the village of Marzoi Mokhk in the Vedeno district during a police raid, lasted about 90 minutes. Police are now searching for the gunmen involved in the clash, the source added. Large-scale conflicts between federal troops and separatists are over in Chechnya, but militants continue to stage regular attacks on federal troops and Kremlin-backed police and authorities. The neighboring regions in Russia`s volatile North Caucasus have also been plagued by sporadic militant attacks.