Chinese authorities are working to protect the quake survivors in the northwestern province of Qinghai from potential secondary disasters.

The government has provided sufficient food, drinking water and tents for more than 200,000 quake survivors, but landslides, floods and disease outbreaks may still threaten their lives.

The magnitude 7.1 quake has killed at least 2,220 people, with 70 still missing and more than 12,000 injured.

Recent rain has raised the risk of landslides as the devastating quake and aftershocks has destabilized mountain slopes. The rainy season starting in late May or early June will make the situation worse.

A total of 139 survivors were evacuated to safety 7 km away from their make-shift homes in Changu Village of the quake-hit Yushu Tibetan Autonomous Region early Tuesday morning as rain-triggered landslides threatening their safety.

"It's still an arduous task to prevent and guard against secondary disasters," said Wang Jianbin, deputy director of the Qinghai provincial land and resources bureau.

In the hardest-hit Gyegu Township where 85 percent of the buildings collapsed, potential secondary disasters in 10 areas posed threats to the safety of 1,924 residents, Wang said citing an initial survey.

Lu Baoliang, a senior engineer at the provincial geology and environment monitoring station, said they were sending experts to check potential secondary disasters in 57 villages.

Yu Congle, director of the provincial water resources bureau, is increasingly worried about the coming rainy season as Gyegu Township is at the intersection of two rivers.

Gyegu is often plagued by flash floods in normal years. In addition, the earthquake has damaged river dikes and blocked seven out of eight flood discharge tunnels.

"Many survivors and rescuers living in tents beside rivers will face threats from flooding," Yu said. "But we will never let the quake-hit region be wrecked by flooding."

The local water resources authorities are reinforcing the river dikes and unplugging the flood discharge tunnels, Yu said.

Local authorities have properly disposed of more than 40,000 dead animals to prevent outbreaks of infectious diseases.

But Yushu's more than 30,000 stray pets are a concern as they might eat dead marmots carrying the plague, and then transmit the disease to humans.

The local health authorities have sent out 137 medical workers in seven groups to guard against any outbreaks of infectious diseases. They also have set up a testing laboratory for the plague.

"It's our top guiding principle to ensure the safety of residents. We will never let them suffer a second trauma," said Luo Huining, governor of Qinghai Province.