Russian President Vladimir Putin has paid a rare visit to Chechnya and pledged to send extra troops following the assassination of a key ally there. Mr Putin described the killing of Moscow-backed Chechen leader Akhmad Kadyrov as a \"lesson\" to Russia. More than 1,000 extra Russian troops will be sent to the Caucasus republic. Chechen guerrillas fighting Moscow\'s rule have been blamed for Sunday\'s bomb attack in the capital Grozny, in which at least seven people died. The latest victim was a young boy who died of head injuries, hospital officials said. Recent estimates suggest there are up to 80,000 Russian troops in Chechnya. This figure includes regular soldiers and the Kremlin-backed Chechen militias that work alongside them, according to Tom de Waal from the Institute of War and Peace Reporting. But exact numbers for the Russian military presence are not available. Plans to move the injured Russian commander Valery Baranov to Moscow have been delayed because of his critical condition. He was due to have been evacuated to Moscow for further treatment on Tuesday, but is now likely to leave on Wednesday, the Russian military said. Gen Baranov, Moscow\'s top military commander in the region, was at a victory ceremony with President Kadyrov when a bomb blast ripped through their enclosure at a stadium in Grozny. Mr Kadyrov, a Muslim cleric who once sided with the separatists before switching to become the Kremlin\'s favoured son in Chechnya, died almost instantly. Correspondents say the bombing has left Russia\'s Chechnya policy in tatters, after President Putin had claimed to have silenced the separatists. (BBC)