Japanese defense officials say to Russian bombers took an unusual course circling around Japan. The Defense Ministry says to TU 95 bombers from the Russian Air Force approached Japanese airspace near the Strait of Tsushima on Thursday morning. Fighter planes from Japan's Air Self Defense Force scrambled to track the bombers. Aircraft later flew southward over the east China Sea and then south of Okinawa's main island. Afterwards, it moved to the Pacific side before skirting along the Japanese archipelago northward. The bombers continued flying over the Strait of Tsoya while being fueled midair. They then headed south on the Japan Sea side before leaving areas near Japan. The Defense Ministry says the bombers did not violate Japan's airspace, but it was an unusual route for any Russian military aircraft. The Russian Air Force has been active around Japan recently. Bombers and spy planes have approached Japanese airspace five times since last month. The Electric Park Company or Teppko has begun stress test on the idol nuclear reactors in Nihiga-Takrifecture. The tests were imposed by the Japanese government as a condition before reactors are put back online. Teppko began a test on Friday at two of the seven reactors at the Kashiwazaki-Kariwa nuclear plant. The utility plans to assess their resistance to earthquakes and tsunamis through a series of computer simulations. The next step will be to obtain the approval of local authorities, but so far opinions remain divided. If the safety of the reactors is confirmed by the stress test, there is no reason to keep the power station offline. The Governor of Nihiga-Takrifecture appears more reluctant. He says the proper assessment of Fukushima accident will be needed before the reactors can be restarted.