A four-year-old girl was injured on Wednesday when insurgents attacked a Border Security Force patrol at Maphou village in Imphal.
BSF personnel who were on guard the Maphou dam escaped unharmed in the blast that took place around 9 a.m.
The girl was rushed to a private hospital. Reports said she was out of danger.
Attackers escaped through Maphou mountain in Ukhrul district. No combing operation was launched since the police feared the militants might have escaped to their camps.
Deputy Chief Minister Gaikhangam Gangmei has asked all police stations as well as camps of the paramilitary forces and central forces to be on alert.
Leaves of all security personnel have been cancelled.