WASHINGTON (AP) -- A U.S. military helicopter carrying six Marines and two Nepalese Army soldiers went missing during a mission in Nepal delivering aid to earthquake victims, U.S. defense officials said Tuesday, but so far there have been no indications that the aircraft crashed.

A Mexican rescue worker stands at the site of a building that collapsed in an earthquake in Kathmandu, Nepal (AP Photo/Niranjan Shrestha)

U.S. Army Col. Steve Warren said an Indian helicopter in the air nearby at the time heard radio chatter about a possible fuel problem. He said the Huey had dropped off supplies in one location and was en route to a second site when contact was lost. He said officials are hopeful that the aircraft is simply missing because there has been no smoke or other signs of a crash.

Navy Capt. Chris Sims says the Huey was conducting disaster relief operations near Charikot, Nepal, on Tuesday, around 9 a.m. EDT.

Warren said other U.S. aircraft had searched the area, but because it's now dark members of the Nepalese military are conducting the search on foot. He said they are moving toward the second aid location to see if the helicopter landed near there.

The aircraft is part of Marine Light Attack Helicopter Squadron 469.

The incident is under investigation.

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