Terence Mak, assistant police commissioner, said “some radical protesters” had “harshly attacked some innocent visitors.” He likened the assaults on the two men to torture and added that paramedics were blocked from immediately treating them.

“What did these visitors do to deserve such suffering?” Mr. Mak said.

On Wednesday, protesters seemed well aware of the negative image they had presented. “We apologize for our behavior but we are just too scared,” read one post on a messaging channel used by protesters, which gained wider distribution on other social media. “Our police shot us, government betrayed us, social institutions failed us. Please help us.”

“Please accept our sincere apology to all travelers, press reporters, paramedics,” read another post. “We will learn from our mistakes. Please give us a second chance to prove ourselves that we can be better.”