Rescuers had excavated a 236-meter-long tunnel to reach the 16 miners who had been trapped in a flooded colliery pit in central China's Hunan province for over 60 hours, local authorities said Saturday.

As of 7:00 a.m., the distance to reach the trapped miners from the excavated tunnel is very close, but huge rocks in the passageway hampered rescue efforts, said rescuers at the scene.

The miners were trapped in a pit of Qielichong colliery in Sandu township, Leiyang city, following a mine flood at 6 p.m. Wednesday. Of the 40 people working in the pit, 24 managed to escape.

But the accident was not reported to the local government until 6:30 a.m. Thursday, which delayed the start of the rescue operation by almost 12 hours, according to the publicity department of Leiyang City Communist Party Committee.

Six professional teams of 90 members and more than 1,000 people were sent to the scene to carry out rescue operations.

Flood water was drained out and ventilation in the shaft was resumed on Thursday morning.

Rescuers have not established contact with the trapped workers so far.

The mine owner, Liu Yaping, is under police custody.