Workers install welded metal plates around the entrance of a China Merchants Bank branch in Hong Kong on Oct. 25. (AP Photo)

HONG KONG--As Hong Kong's protest movement becomes increasingly violent, some shops are battening the hatches.

Banks, retailers, restaurants and travel agents with ties to mainland China or perceived pro-Beijing ownership have fortified their facades over apparent fear of further damage after protesters trashed businesses following a recent pro-democracy rally.

Branches of state-owned Chinese banks across the city reinforced their glass fronts with walls of steel on Friday.

A Japanese noodle chain, a sushi chain and Starbucks outlets that have been targeted by protesters also covered up their shopfronts with wooden panels. The three are reportedly operated by a restaurant company founded by a tycoon whose daughter has denounced the protesters.

The protesters have been rallying since June for full democracy and police accountability. But the rallies have ended in increasing violence as protesters throwing firebombs are met by police with tear gas, pepper spray and water cannons.

Protesters set fire to Chinese bank branches and Chinese smartphone brand Xiaomi's boutique on Sunday after an unauthorized rally by tens of thousands of people.

A welder put the finishing touches on grey steel panels covering up an Industrial and Commercial Bank of China branch in the city's Wan Chai district.

Across the street, a state-owned China Travel Service outlet was getting the same treatment.

Signs at a nearby China Construction Bank branch said "enhancement work was in progress" but it was business as usual and apologized for the inconvenience.

Staff at the businesses refused to comment.

A passing pro-democracy supporter, restaurant manager Tim Lo, said it wouldn't solve the root cause of the conflict.

"Barricading is useless," he said.