Hong Kong ( CNN ) -- China on Friday denied accusations by Japan that a Chinese navy vessel had put a radar-lock on a Japanese warship near a group of disputed islands at the heart of a bitter feud between the two Asian nations . The Chinese Ministry of National Defense said in a statement , its first official response to the claims , that Japanese officials had given out `` false information '' and `` hyped up '' the threat from China . Opinion : Is Asia sleepwalking into war ? The Japanese allegations this week have put a fresh strain on relations between Tokyo and Beijing , which remain at loggerheads over who has sovereignty over the remote , rocky islands in the East China Sea . The tensions have resulted in maritime standoffs and the scrambling of fighter jets in recent months . Japan currently administers the islands , but China has been regularly sending its own vessels on patrols in the surrounding waters . Japanese Prime Minister Shinzo Abe on Wednesday described as `` dangerous '' and `` regrettable '' the actions of the Chinese frigate that Tokyo says used radar to gather information on the location of a Japanese destroyer in the East China Sea last week . That type of radar could be used to produce data needed to fire upon the Japanese vessel . Read more : How a remote rock split China and Japan . But the Chinese defense ministry said Friday that its navy vessel 's radar maintained `` normal operations '' and that it did n't use the fire-control radar . It also denied accusations that its navy put a radar-lock on a Japanese helicopter earlier in January , saying that Tokyo 's claims did n't match the facts . `` Japan unilaterally released false information to the public without confirming the facts with China , '' the ministry said . Tokyo unimpressed . But the Japanese government stuck by its account and expressed dissatisfaction with the Chinese statement on Friday . `` Japan can not accept the Chinese explanation and urged a sincere response from China on the matter , '' Foreign Minister Fumio Kishida said . The Japanese foreign ministry summoned the Chinese ambassador to Tokyo over Beijing 's denial of the radar incident . The United States expressed concern earlier this week about the alleged radar-locking on the Japanese ship . Interactive : Asia 's disputed islands -- who claims what ? `` Actions such as this escalate tensions and increase the risk of an incident or a miscalculation , and they could undermine peace , stability and economic growth in this vital region , '' Victoria Nuland , the spokeswoman for the State Department , said Tuesday . The United States has tried to avoid getting dragged into the island dispute , saying it does n't take sides on such competing claims of sovereignty . But U.S. officials have admitted that the islands fall under a mutual security treaty between Washington and Tokyo . The Japanese call the disputed islands Senkaku , and China refers to them as Diaoyu . Near them are important shipping lanes , rich fishing grounds and possible mineral deposits . Competing claims . Disagreement over who owns the small , uninhabited islands has soured diplomatic and economic relations between Japan and China since September , when Japan announced it had bought several of the islands from private Japanese owners . China was outraged , as were protesters who marched through several Chinese cities calling for boycotts of Japanese products and asserting Beijing 's sovereignty over the islands . Some of the protests turned violent , and damage to Japanese offices and businesses was reported . In December , the dispute escalated when Japan scrambled fighter jets after a Chinese plane was seen near the islands . Chinese ships have repeatedly entered contested waters despite warnings from the Japanese Coast Guard . China says its claim extends back hundreds of years . Japan says it saw no trace of Chinese control of the islands in an 1885 survey , so formally recognized them as Japanese sovereign territory in 1895 . Japan then sold the islands in 1932 to descendants of the original settlers . The Japanese surrender at the end of World War II in 1945 only served to cloud the issue further . The islands were administered by the U.S. occupation force after the war . But in 1972 , Washington returned them to Japan as part of its withdrawal from Okinawa . Tensions with Russia . Japan was given an abrupt reminder of a separate territorial dispute on Wednesday when its defense ministry said two Russian fighter jets entered Japanese airspace near the tip of the northern Japanese island of Hokkaido . The Russian jets left Japanese airspace without incident after a little more than a minute , the ministry said . The incident occurred near a set of islands disputed by Tokyo and Moscow since the end of World War II . Russian officials denied their jets entered Japanese airspace , the Russian news agency Interfax reported . CNN 's Jethro Mullen reported and wrote from Hong Kong , and Yoko Wakatsuki reported from Tokyo . CNN 's Dayu Zhang in Beijing contributed to this report .
The Chinese defense ministry says Japanese statements do n't match the facts . It denies a Chinese frigate put a radar - gun on a Japanese ship . It expresses dissatisfaction over the Chinese response . The entire incident occurred near a group of disputed islands .