The massive earthquake that hit a southwestern Chinese province Sunday has killed at least 398 people, injured about 1,800, and left emergency response teams scrambling to find survivors.

According to the U.S. Geological Survey, the 6.1 magnitude (6.5, reported the China Earthquake Networks Center) struck Ludian County, marking an epicenter about 20 miles away from Zhaotong, a city home to about 5.2 million people. The earthquake has toppled about 12,000 buildings in Yunnan province, leaving many trapped under the rubble. China's Xinhua News Agency has reported that the fragile foundations of houses contributed to much of the destruction:

Reuters

The latest reports from Xinhua number about 70 people pulled from the rubble, with about 30 alive. 

Rescue efforts have largely been hampered by the persisting rainfall, and the Chinese state media has released a call for people to avoid blocking the roads for emergency workers to enter the areas. 

Additionally, China has sent 2,500 soldiers to the province to aid rescue efforts, bringing with them life-detection instruments and digging equipment—essential tools for rescuing those trapped in buildings, as people rarely survive more than 48 hours under rubble, according to the WHO. The soldiers join the 300 police and firefighters from Zhaotong and 400 emergency workers and sniffer dogs already in place.

China President Xi Jinping has called for "all-out efforts" to find survivors. In total, the central government has allocated about 600 million yuan ($97 million) to rescue and relief work. The amount includes the 2,000 tents, 3,000 folding beds, 3,000 quilts, and 3,000 coats provided to the disaster zone for survivors.

Reuters

CCTV reported the earthquake is the strongest to hit the mountainous province in 14 years, though the area has always been prone to massive earthquakes: In 2008, an earthquake in Sichuan left 90,000 people dead or missing. In 1974, a magnitude 7.1 quake killed more than 1,400 in Yunnan, and in 1970, a 7.7 magnitude quake in the same province killed at least 15,000. 

International responses have poured in as well. The White House offered condolences Sunday, with National Security Council Deputy Spokeswoman Bernadette Meehan releasing a statement saying, "Our thoughts and prayers are with the families of those that lost their lives. The United States stands ready to assist."

U.N. Secretary-General Ban Ki-Moon echoed the sentiment, stating that the U.N. is ready to "lend its assistance to efforts to respond to humanitarian needs" and "to mobilize any international support" if necessary.

About 230,000 people have been evacuated from the region, and the death toll is expected to rise as rescue workers uncover more rubble.