MOSCOW (AFP) - Six crew members, including two Myanmar nationals, died when a plane they were testing crashed in central Russia on Saturday, the Russian emergency ministry said. The six died when the AN-148 plane crashed and burst into flames on Saturday morning around 160 kilometres (100 miles) east of the city of Belgorod, the ministry said in a statement, citing preliminary data. The dead included two citizens of Myanmar, along with two pilots and two flight engineers who were Russian citizens, the regional emergency ministry said. The Myanmar citizens were identified as Htein Lin Aung and Zaw Htun Aung. In conflicting reports, a spokesman for the investigative committee's military section said that seven people died, according to the Interfax news agency. The investigative committee said six were dead in an official statement. A source at the Voronezh aircraft factory, which built the plane, told the RIA Novosti agency it was undergoing tests prior to being sent to Myanmar. "The plane had been tested for two weeks. This was its first flight today. It was being prepared for Myanmar," the source said. The plane disappeared from the radar at 10:40 am (0740 GMT), and a plane flying over the area later spotted a fire where it crashed, the source said. Russian television showed flames ripping through the wreckage and black smoke billowing from the crash site in a snowy field close to wooden houses and trees. A witness cited by the Interfax news agency said the plane appeared to burst into flames before hitting the ground. "I saw the plane starting to circle over the school, then it burst into flames and fell on the vegetable gardens of the villagers," the agency cited a witness living in the village of Garbuzovo. The Investigative Committee said in a statement that it had opened a criminal investigation into breaches of flight safety rules. A source told Interfax the pilots from Myanmar had not trained on flight simulators. "If they were at the controls, it could have led to the air crash. The plane could have fallen into a spin." The AN-148, designed by Ukraine's Antonov factory and built by Voronezh aircraft factory in a joint project, is a jet liner with a regional range that can be used for passengers and cargo. Russian newspaper RBK daily reported in November 2009 that Russia planned to supply Myanmar's defence ministry with two AN-148 planes in 2010, to be built at the Voronezh factory, citing industry sources. Western governments have imposed sanctions on investment and travel over human rights abuses in military-ruled Myanmar. Last month, EU lawmakers urged China, India and Russia to pressure Myanmar to improve human rights and to stop supplying arms to the regime.