Beijing, China (CNN) -- China on Thursday released three Japanese nationals after they admitted illegally entering a Chinese military zone and expressed regret, state-run media said.
Another Japanese national, who worked with the three, remained under house arrest for illegally videotaping military targets and an investigation was continuing, the Xinhua News Agency said.
"We will continue our effort to rescue the one left behind," Fujita Corp., the company that employs the four Japanese nationals, said Thursday.
Fujita said it did not know the whereabouts of the three whom China had released.
All four Japanese nationals were arrested in Hebei Province on September 23 as Beijing and Tokyo clashed over the arrest of a Chinese fishing captain by Japan.
The captain was taken into custody in early September off the disputed Diaoyu Islands, in the East China Sea. His arrest touched off a battle that escalated into diplomatic threats by Beijing, the suspension of diplomatic talks and canceled trips between the nations.
CNN
