The 172 miners trapped in a flooded mine in eastern China nearly three weeks ago were pronounced dead Thursday as officials cited bad management as a main cause of the tragedy, state press said.

The miners "will not return alive," Xinhua news agency quoted a statement from the Shandong provincial government as saying.

Heavy rains caused a nearby river to burst its banks on August 18, flooding the Zhangzhuang coal mine near the city of Xintai.

Rescue operations have focused on pumping the water from the pit, but none of the missing have been found, according to AFP news agency.

There was no news about the fate of nine other workers trapped the same day in a flood at the nearby Minggong coal mine, Xinhua reported.

Although officials had previously insisted the tragedy was simply a natural disaster, State Administration of Work Safety chief Li Yizhong said this week that poor planning and inadequate safety procedures were also to blame.

"The root (problem) is some local authorities and companies have failed to take sufficient action to tackle safety loopholes and build a sound early-warning mechanism," Li said in comments carried by the China Daily.