Dozens of police rescuers were scouring a remote area in northwest Nepal on Wednesday looking for five villagers who went missing after being hit by an avalanche while searching for a valuable aphrodisiac herb, an official said.

Four women and one man were missing since Tuesday when an avalanche hit their camp at the village of Byas while seven others escaped, Darchula district official Pradip Singh Dhami said by phone. The area lies about 500 km (312 miles) northwest of the national capital of Kathmandu.

"The search for the missing villagers has been hampered by continuous snowfall and rain in the area," Dhami said.

Hundreds of villagers go to the foothills of the Himalayas during the summer to pick up the fungus-like herb, which is also known as the "Himalayan Viagra".

Sixteen villagers collecting the expensive herb were killed in the remote Dolpa region bordering China during a heavy snow storm in 2007. (Reporting by Gopal Sharma; Editing by Christian Schmollinger)