Early on Saturday a Russian army convoy came under fire in the  mountainous south of Chechnya, Interfax reported citing the interior ministry.

  

A sergeant was critically wounded and an operation had been mounted to hunt down those responsible, Interfax said.

  

Attacks on Russian federal troops and local officials loyal to Moscow remain frequent in the breakaway Caucasus province, despite Moscow declaring victory in a second war to crush the separatist rebellion there.