Police and rescuers continued to search on Monday for a Shanghai hiker who has been missing for 20 days in remote areas of the Xinjiang Uygur autonomous region, denying media reports that said they have stopped searching.

A task force with a Kazak ethnic group background is searching for the missing man, Xu Guang, in the depopulated zones, police in Altay prefecture said on Monday.

"We never said we were giving up the search and rescue efforts," police said. "Instead of giving up, police are actively preparing for the next round of rescue."

News of suspending the rescue efforts hit headlines on Monday after a man with the Xinjiang Shanyou Mountain Rescue Team told a regional newspaper that their search efforts had been thwarted since Wednesday by the difficult landscape and hopes of finding him were slim.

The non-government Xinjiang Shanyou Mountain Rescue Team and two other rescue teams that police sent on Thursday have returned after they tried in vain to find him in the designated search areas.

But on Monday, Yang Jun, head of Shanyou, the largest non-government rescue team in Xinjiang, told China Daily that they will continue to assist police to locate Xu, a veteran hiker who had been trekking alone near Kanas Lake since June 10.

The biggest threats to the rescue efforts come from the high mountains, dense forests and wild animals in the area including bears and wolves, Yang said.

"In those conditions, we have to trek on foot most of the time, though we can sometimes ride on horseback to search in areas where the forests are not that dense," he said.

"We have a veteran hunter with us and have borrowed guns and ammunition from armed police in case of wild animals," he added.

But the search has been extremely difficult because Xu left no traces at all during his hike. It is also possible that any traces have been destroyed during the flood season in the vast, sparsely populated zones in Northwest China.

"There are no signs of him sitting on the grass, camping or breaking tree branches at all," Yang said. "The only clues he left are the short text messages and pictures he sent back when his mobile phone had a signal."

The chances of him surviving have become very slim, he added.

Xu, an IT engineer in his 30s, left Shanghai on June 8 and was supposed to take a return flight after completing his adventure on June 19.

But he has been out of contact since June 10, when he texted his father saying that he had drawn close to the Kanas area, alerting him that there may be no cell phone signal for the following trip, and asking him not to worry.

On June 21, his family alerted police when officers started to search for him based on a planned travel route Xu released earlier in an online forum.

His family and friends have also left messages on popular hikers' forums to ask other explorers to report Xu's whereabouts if they happened to meet him or found signs of him in the remote areas.

"I've tried several forums but have yet to receive any useful information," Zhao Ping, one of Xu's hiking friends, said on Monday. "His family has been worrying for him, and I hope he is safe and sound."

As more people enjoy mountaineering and outdoor activities in China, the number of such accidents has risen significantly in recent years.

Dozens of people die each year in mountaineering accidents and while participating in outdoor sports in China, according to the Chinese Mountaineering Association, and experts call for more careful plans and great caution when embarking on dangerous adventures.

"Adventure is always popular, but the stress is on doing it in a scientific way now and that does not mean risk-taking," said the Xinjiang Shanyou Mountain Rescue Team's Yang.

Before going on a trip, the hiker should leave enough safety information, make a detailed evaluation for potential risks on the route and prepare emergency plans, he said.

"In Xu's case, if he had briefed local governments about his hiking plan before his adventure, or shared stories with the owners of inns he lived in en route, the search and rescue efforts wouldn't be so tricky," Yang said.