Banks in Guangzhou were starved of money on Tuesday as thousands of security van workers took to the streets to protest against low pay and long hours.
The strike, which lasted about 12 hours, left major financial institutions, including the "big -four" state-owned banks, stranded without cash, Chinese media reported.
The rare protest by van drivers and security guards, mostly young male workers employed by the state-owned Sui Bao Escort & Convoy Corporation, happened days after an on-duty operator accidentally shot himself and later died.
The workers, who gathered near the campany's entrance and demanded to speak with management, told reporters they were only paid 2,000 yuan (HK$2,542) a month.
Mostly in their 20s and 30s, they said they experienced problems with relationships because they had to work more than 12 hours a day.
The workers also complained about the unsatisfactory accommodation supplied by the firm, with many saying they had to sleep on bunk beds in dormitories shared between 20.
The city's police chief and mayor subsequently intervened and facilitated negotiations between the staff and their employer, reports said.
Li Shu, a manager at the firm, told the China Business News that the company had agreed to a 600-yuan pay rise effective from February 21.
Conditions had returned to normal by the evening, Guangzhou police said late on Tuesday.
A spokesperson from the company confirmed to the South China Morning Post on Wednesday that operations had resumed at around 6pm on Tuesday. Most workers were happy with the pay raise, she said.