(RIA Novosti) - Four members of illegal armed groups have surrendered in Chechnya, a police source in the troubled Russian republic in the North Caucasus said Thursday. Through a partial amnesty announced on July 15, following the killing of the region's number one terrorist Shamil Basayev, militants not involved in major atrocities were promised leniency.One of the militants surrendered in Gudermes, Chechnya's second largest city situated in the east of the republic. He is said to have fought against federal troops in the region since 1995. The three others gave themselves up in the republic's central and southern districts. The police spokesperson said the militants also surrendered their arms.