An earthquake of magnitude 6.2 hit one of the poorest regions in China late on Monday night, destroying or damaging more than 150,000 homes, forcing the evacuation of tens of thousands of people and damaging vital infrastructure.

As of Wednesday morning, according to the state media, at least 134 people were killed and around a thousand injured in northwestern Gansu province and the neighbouring province of Qinghai. The toll could rise as rescuers search for survivors in very cold conditions, with temperatures of minus 16 degrees Celsius on Tuesday morning.

In Gansu, the worst-affected province, some 87,000 people have been moved to temporary shelters. The injured have either been sent to hospital or treated at a mobile field hospital set up by the Gansu Provincial Peoples Hospital’s emergency medical relief team, equipped to carry out emergency surgical operations.

Reporting from the sixth commune of Dahe village in Gansu province, the state media found many houses were either at risk of collapse, or had already crumbled to the ground. Many homes were built from earth and clay. An old man being carried out of his damaged home said: “I’ve lived for more than 80 years and had never seen such a big earthquake.”

Conscious of the disaster’s potential to trigger social unrest, Chinese President Xi Jinping called for “all-out” search and rescue efforts and assistance to the people affected by the earthquake, including for their resettlement.

The rescue and relief effort has involved about 2,200 personnel from the Gansu provincial fire department and 900 from the forest brigade, as well as 260 professional emergency rescue workers, according to the Xinhua news agency. Hundreds of military personnel and police were also sent.

Officials from the hard-hit county of Jishishan told the media that they lacked the resources to cope with the disaster and had to rely on the provincial government. The county has a population of around 260,000 people, mostly spread out in villages and townships.

The Gansu provincial government allocated 20 million yuan ($US2.8 million) for the emergency work and also sent supplies of cotton tents, beds, quilts, cotton mattresses and stoves.

In phone interview with Agence France Presse on Tuesday, Ma Dongdong explained that his home had been destroyed and his business, a milk tea shop, damaged. “I just feel anxious, what other feelings could there be?” he said.

Ma spent the first night in a field with his wife, children and some neighbours huddled around a fire, as they were fearful of returning home due to aftershocks. They went to a tent settlement housing about 700 people the following morning but by the afternoon were still waiting for blankets and warm clothes.

The earthquake, at a depth of 10 km, struck Jishishan county on Monday just before midnight. The epicentre was 5 km from the provincial border between Gansu and Qinghai. Nine aftershocks of magnitude 3.0 and above were recorded by Tuesday morning. Two of those were greater than 4.0 in magnitude.

Li Haibing from the Chinese Academy of Geological Sciences told the media that that the relatively high number of casualties was in part because the quake was shallow and mainly a vertical motion, causing more violent shaking. Li also pointed to the low quality of buildings in the relatively poor region and the fact that the quake took place in the middle of the night.

The earthquake also triggered landslides and half buried one village in silt. In the village of Jintian, the homes of 36 families, totalling 177 villagers, were destroyed by sand boils. As of yesterday, 13 people were still missing, including a pregnant woman. Four bodies had been found by rescuers.

Villages like Jintian are in a dry area, near no river and have seen no rainfall. Asked why it had suffered a severe landslide, Wang Tun, head of an earthquake early warning laboratory in China’s Sichuan Province, told the Global Times that a strong earthquake, due to its violent impact on the Earth’s crust, can liquify water-saturated sand and soil situated deep underground, then force the liquid sludge to the surface.

A rescue worker told the Global Times that rescue work in Jintian village had been difficult as the mud made it impossible for workers to walk. A floating bridge had to be constructed of wooden planks to reach the affected area.

Earthquakes are virtually impossible to predict with any accuracy. However, the South China Morning Post reported that researchers in the Chinese province of Shaanxi have developed a method that has enabled them to forecast every quake with a magnitude of 7.0 or more in the past 10 years, but not their exact locations.

The researchers said they knew the latest earthquake was on the way when they received a text alert about abnormal data readings from multiple sensors. They calculated that a quake of magnitude around 6.27 had a high probability of hitting within three to five days, but not where precisely.

Earthquakes are common in China’s western provinces such as Gansu, which lies on the boundary of the tectonically active Qinghai-Tibetan plateau. China’s deadliest quake in recent decades was in 2008 when a massive tremor of magnitude 8.0 struck the province of Sichuan, killing nearly 70,000 people.

The Sichuan disaster provoked an outpouring of anger from victims who had lost their loved ones in schools and other buildings that collapsed. Relatively new schools were flattened a matter of seconds, making it impossible for children to escape, while surrounding buildings were still standing. Angry parents denounced the schools as substandard “Tofu” projects in which corrupt local officials and businessmen had siphoned off public money.

In a bid to assuage public anger, the Chinese government committee was finally forced to acknowledge that shoddy workmanship and substandard materials were behind the collapse of some 7,000 school classrooms.

Today, under conditions of rapidly worsening social tensions, Xi’s call for an “all out” effort following the latest earthquake has the character of a pre-emptive action to head off any outburst of public questioning and anger. Xi declared the eradication of “extreme poverty” in China in 2021, but the dismal photos of collapsed earth and clay dwellings speak otherwise.