Thiruvananthapuram, Nov 13 : The Kerala Police on Monday engaged in an encounter with Maoist in Kerala's Kannur district after the outlawed group opened fire on them deep inside the forest. According to authorities, the ThunderBolt squad -- formed to tackle the Maoists menace --was on a routine surveillance in the deep forests early this morning when they saw two Maoists who opened fire on them. In retaliation, the police fired back leading to an exchange of fire for some time, the locals said. After half an hour, police inspected the area and saw blood marks besides recovered three guns. The police team said their team suffered no injuries. After the exchange of fire, the two Maoists are understood to have escaped into the deep forests bordering Karnataka. Incidentally, the police had increased their surveillance after October 30 when forest watchers who were going into the forest camp with food were fired upon by a five member Maoists gang. Last week, the Kerala Police nabbed two Maoists from the same area. On Monday, a local court granted the custody of the two, including a woman, to police till November 22. /IANS