HONG KONG, China (CNN) -- Retailers in the Chinese city of Urumqi, which witnessed deadly protests last weekend, and other cities in the region have resumed business, the Xinhua news agency reported Sunday, citing China's Ministry of Commerce.

Police patrol Urumqi, China, on Saturday, July 11.

In a statement on its Web site, the ministry said Sunday that supplies of meat, vegetables and other daily necessities were "abundant," Xinhua said, and that prices had fallen before the levels of violent demonstrations on July 5.

At least 184 people were killed in the demonstrations and more than 1,600 injured, according to government figures. Heavily armed troops remained on the streets of Urumqi over the weekend, and curfews were in effect.

"Assemblies, marches and demonstrations on public roads and at public places in the open air are not allowed without the permission by police," read a notice by the Public Security Bureau of Urumqi, Xinhua said Saturday.

The Ministry of Commerce said in its statement that it has sent a working group to the Xinjiang Uyghur Autonomous Region to help local governments "step up efforts on guaranteeing the market supply of meat, vegetables and other daily necessities, ease price hikes and regulate the market order," Xinhua said. The ministry said a total of 1,500 tons of vegetables was shipped to Urumqi last week.

Meanwhile, an explosion occurred Sunday morning at a refinery in Urumqi, Xinhua said. The blast at the China National Petroleum Corp. was extinguished by midday. No casualties were reported and no links to sabotage were found, Xinhua said.

It was not clear what caused the explosion, but the incident was under investigation, Xinhua said.

The Urumqi security measures on public assembly came on the eve of a sensitive day of mourning, media reported. It is traditional for ethnic Han to mourn their loss on the seventh day after a death, the South China Morning Post reported.

The violence was a result of ethnic tensions between the Uyghurs, who are predominantly Muslim, and members of China's Han majority. Hundreds of Han Chinese were on Urumqi streets Tuesday, holding sticks and pipes, and calling for punishment of the Uyghurs, who they say committed serious crimes.

The Uyghurs say they have been victimized and that many of those killed in the violence were Uyghurs. Uyghur religious leaders condemned the violence, saying it is against the spirit of the Muslim faith and Uyghur tradition.

In Turkey, Prime Minister Recep Tayyip Erdogan continued his outspoken criticism Saturday of China's crackdown on the Uyghurs.

In remarks published by the official Anatolian Agency, Erdogan denounced what he called "savagery" and called on the Chinese government to "give up efforts to assimilate" the country's Uyghur minority.

Erdogan told journalists on his return to Ankara, Turkey, from the G8 summit in Italy that "the incidents in China are a genocide. There's no point in interpreting this otherwise."

Many Turks view the Uyghurs of central Asia as fellow Turkic, Muslim brothers.

All About China • Protests and Demonstrations • Xinjiang Uygur Autonomous Region