Eight Indian tourists died after they were found unresponsive in a hotel room in Nepal.
The two couples and four children were found unconscious and were all pronounced dead at hospital.
They were part of a group of 15 from Kerala who had booked four rooms at the Everest Panorama Resort.
However all eight who died were sleeping in the same room.
"They were found unconscious this morning and airlifted to Kathmandu but died during treatment," police spokesman Shailesh Thapa Chettri told AFP.
"We suspect they died of suffocation, but autopsy reports will confirm the cause."
They were using a gas heater to stay warm and windows were bolted.
The hotel is in Daman, which is a popular destination about 55 km from Kathmandu.
The gas heater and lack of room ventilation is being looked at as a probable cause of asphyxiation although Nepal authorities have opened a full investigation.
