Beijing (CNN) -- A rash of violent protests in China continued over the weekend as migrant workers and security forces clashed in a rural city about 60 miles northwest of Hong Kong, local government officials and witnesses said.

The protest erupted in Zengcheng over what witnesses described as rough handling of a pregnant street vendor by security guards Friday. Local government officials said the protests involved hundreds, while other unofficial reports estimated tens of thousands of protesters.

The demonstrators hurled bottles and bricks at government officials and marched to the local police station, where they damaged several cars, according to the local government officials. Protests continued Saturday and Sunday, according to local officials.

The situation in Zengcheng remains tense, according to a businessman who asked to be identified only by his surname, Hu, because he was concerned about reprisals from government officials.

Looting and violence is widespread at night, despite the presence of security forces, according to Hu, who said he witnessed nighttime violence before deciding it would be safer to stay inside at night.

The Zengcheng riot is the latest disturbance in China, whose government is apparently unnerved by scenes of masses of protesters across the Middle East and North Africa seeking, and in some cases winning, reform from their governments.

"Because of the Arab Spring and economic insecurities people face in China, the government has been cracking down even harder on protests, even if they are of a local nature," said Patrick Chovanec, a political analyst at Tsinghua University's School of Economics and Management in Beijing.

Last week in Lichuan, protests broke out after the prison death of a local government official who had been charged with bribery.

The local government said the death of Ran Jianxin was still under investigation. They said that two local officials had been suspended and were under investigation in his death. Two others involved in the corruption case against Ran were in custody, according to the local government.

Residents said they believed Ran was killed for not cooperating with other corrupt officials.

A YouTube video showed people gathered in front of government buildings with a banner reading, "(Ran) offended the officials for the benefit of the people, and he was murdered."

Large protests also continued last week in Inner Mongolia, when thousands of ethic Mongolians swarmed security officers after the death of a Mongolian who had been hit by a coal truck driven by an ethnic Han Chinese.

In late May, thousands of Mongolian students protested in support of the herder in Xilin Gol. And Chinese authorities arrested dozens of demonstrators in Hohhot last month as protests spread to the provincial capital and other cities in Inner Mongolia despite tightened security and reports of martial law, activists said.

On Monday, military veterans openly demonstrated at Beijing's railroad ministry, claiming they were denied jobs they had been promised. Ministry officials could not be reached for comment Monday.

CNN's Eunice Yoon, Steven Jiang and Helena Hong contributed to this report.