US Pacific Command said Tuesday an American Marine Corps helicopter offering quake relief in Nepal was declared missing with eight people on board.

The US Pacific Command spokesman Major Dave Eastburn told reporters the disappearance of the UH-1Y Huey helicopter occurred at about 10 p.m. local time Tuesday near Charikot, Nepal, while the helicopter was involved in offering earthquake relief.

Six US Marines and two Nepalese soldiers were on board.

The helicopter was last seen after another helicopter in the vicinity "picked up some (radio) chatter about a fuel problem," Pentagon spokesman Steve Warren told reporters.

"Right now, we are hopeful that there was no crash," said Warren. "There has been no (emergency) beacon, no other signs, no flame, no smoke, no hold in the ground to indicate that there was a crash."

According to Warren, a 90-minute search by three US military aircraft failed to locate the aircraft before nightfall and a ground search by Nepalese troops was underway.

"Essentially what we have right now is truly a missing helicopter. We simply don't know its location," Warren added. He said the "rugged and mountainous" terrain may impede any radio transmissions from the helicopter.

Charikot was one of the villages severely hit by another major quake Tuesday about three weeks after a deadly quake which killed at least 8,000 people and injured 17,000 more.

"A 6.8 magnitude earthquake has hit Nepal at 12:54 and the epicenter is in Dolakha, some 130 kilometers from Kathmandu," Nepalese Home ministry said in a statement. The US Geological Survey had recorded the magnitude of Tuesday's quake at 7.3.

Read more in Special Coverage: