Following inspections, Chinese authorities have closed nearly two dozen Lotte Group stores.

Lotte says that 23 of its supermarkets in its biggest overseas market have been shuttered, reaching from Dandong on the North Korean border to the east coast and southern Changzhou.

Workers at three stores say the closures are temporary and fire-safety related. Its its Sina Weibo microblog, the Anhui fire department says it temporarily shut two Lotte Mart stores because of fire risks, part of a broader regional sweep over the past month that had led to the closure of 30 stores belonging to a range of companies including Lotte.

However, the Lotte closures follow a series of incidents affecting South Korean companies in China, including cyber attacks and a ban on sales of travel tours to South Korea, Reuters reports. Lotte Mart had 115 stores in China as of January, its biggest overseas market, and had group sales there of more than 3 trillion won (US$2.6 billion) in 2015.

Problems started for Lotte after it approved a land swap outside Seoul last month so South Korea could install a defence system in response to missile threat from North Korea.

Meanwhile, photos and videos are circulating on Chinese social media of protests outside Lotte stores, while others show Lotte outlets with their steel grates pulled shut. Outside one store, a red banner reads: “South Korea’s Lotte has declared war on China … Get the hell out of China”.

Lotte Duty Free is back online after a cyber attack last week from Chinese IP addresses crashed its website, and the group is seeking help from the South Korean government regarding the issues it is facing in China, where it employs about 20,000 people – a third of its overseas staff.