Hundreds of police in white protective suits are hunting for bodies in rubble outside Japan’s tsunami-flooded nuclear plant — searching for the first time within a six-mile radius around the radiation-leaking complex.

Police said Thursday that falling radiation levels have allowed them to search within a narrower radius around the Fukushima Dai-ichi plant than before. But they are working very carefully to avoid ripping their protective gear.

Police believe the zone may contain 1,000 bodies of missing victims from the March 11 tsunami. Overall on the northeastern coast, at least 13,400 people were killed and more than 14,800 listed as missing.

Inside the plant, workers are running into fresh setbacks in their struggle to stabilize reactors whose cooling systems were disabled by the tsunami.