An explosion happened at a restaurant inside the Zhongqiao Building at around 12:00 pm, leaving one person dead and at least 23 injured in Dongguan, South China's Guangdong province.[Photo/icpress.cn]

An explosion at a restaurant has left one person dead and at least 23 injured in Dongguan on Monday, jolting the southernmost city which was recently shaken by a massive sex trade crackdown, CCTV reported.

The blast happened at a restaurant inside the Zhongqiao Building at around 12:00 pm during a normally busy lunch hour. The CCTV report said the restaurant was a canteen for a subordinate company of Sino Pec.

Ambulances were immediately called and it was reported that all of the victims work for the company.

Photos posted on Sina Weibo showed rubble made up of shattered glass and chairs from the explosion.

The possible cause of the explosion could be linked to a liquid gas leak.

Dongguan, dubbed "Sin City" in South China's Guangdong province, recently made headlines after CCTV exposed the hideous practices of the city’s sex industry which also triggered a citywide crackdown.

The blast has touched public nerve as the nation is still recovering from a deadly terrorist attack in Southwest China's Kunming on Saturday night, leaving 29 dead.