The level of water in Dhauli Ganga river surged on Thursday which led to temporary suspension of rescue work at the tunnel in Tapovan where 25-35 people are trapped for over four days since the glacier disaster.
The rising water level compelled the security personnel at work inside the tunnel to rush out and also withdraw the heavy machines engaged in drilling through the debris and sludge inside it.
Chamoli District Magistrate Swati S Bhadauria said work has been temporarily halted as a precautionary measure.
The Dhauli Ganga merges with the Alaknanda river system.
On Sunday, a glacier burst at Joshimath in the state's Chamoli district triggered an avalanche and a deluge in the Alaknanda river system that wreaked havoc and washed away hydroelectric stations. The death toll stands at 34 with multiple agencies racing against time to reach 25-35 workers trapped inside a tunnel at the power project site.
(With PTI inputs.)