Chechnya's Moscow-backed leader insists he has not sent troops to Ukraine to fight alongside pro-Russia separatists.In a statement, Ramzan Kadyrov said that as part of the Russian Federation Chechnya had no armed forces, and that any Chechens operating in Ukraine were there in a personal capacity, BBC reported.Monday saw some of the worst fighting since rebels seized much of the east.The separatists say they lost up to 100 fighters as they tried to seize Donetsk airport from pro-Kiev forces.Ukraine's interior ministry says the military is now in full control of the airport, although gunfire was reported in Donetsk itself on Wednesday.A government fighter jet was seen flying over the city.New President Petro Poroshenko has vowed to tackle the eastern uprising. Russia has called for an immediate end to military action.Missing monitorsMany of the separatists involved in the clashes at the airport were reported to be part of a unit called the Vostok (East) Battalion, said to include fighters from the northern Caucasus.In a statement released on Wednesday, Mr Kadyrov said: "Ukrainian sources have been circulating reports that some Chechen units from Russia have invaded Donetsk. I officially declare that this is not true."He added: "There are three million Chechens and two thirds of them live outside the Chechen Republic, including in the West. We cannot know and are not supposed to know which of them goes where."Meanwhile, the Organization for Security and Co-operation in Europe says it has lost contact with a monitoring team. Four of its monitors were on a routine mission east of Donetsk when they were stopped at a checkpoint late on Monday, the security body says.A spokesman told the BBC the men, were Turkish, Swiss, Estonian and Danish. Danish trade minister Mogens Jensen said it was believed they were being held by armed separatists.Meanwhile Poland's foreign minister said that a Polish Roman Catholic priest who had travelled to Donetsk had been abducted by the rebels.Bakudaily.az