Tibetans broke with local burial traditions and began cremating the victims of an earthquake that struck western China more than 72 hours ago, as police stepped up security to avoid looting of relief materials.

The central government has poured in troops and equipment to the remote western region town of Jiegu in a bid to find any remaining survivors, with officials saying the death toll has climbed to 1,144.

There has been tension and some distrust over the government relief effort, which has been slowed by heavy traffic on the single main road from the Qinghai provincial capital, 12 hours away.

The quake struck an ethnic Tibetan area and Tibetans traditionally perform sky burials, which involve leaving the body on a platform to be devoured by vultures.

But Genqiu, who like many Tibetans goes by only one name, said that would be impossible because of the number of bodies.

The government has set up a place to cremate bodies, said Geng Yang, the head of the provincial civil affairs department. "We have cremated 33 bodies so far," he added.

Police said they had increased security at areas where relief supplies were being handed out. "We will severely attack the looting of disaster-relief materials and the stealing of victims' property," provincial deputy police chief Liu Tianhui told a conference held in a tent in Jiegu.

Liu said there were cases of looting straight after the quake on Wednesday, but the situation had improved and "is stable now".

He said the biggest challenge was still getting enough clean drinking water and food for the estimated 100,000 people affected by earthquake.

Though the government was reaching out, many residents turned instead to the monks and their traditions rather than a central authority dominated by the majority Han Chinese.

The groups are divided by language and the government has had to mobilise hundreds of Tibetan speakers to communicate with victims.