UK politicians including a former Foreign Secretary have called on Hong Kong Chief Executive Carrie Lam to order the city's police to show restraint towards protesters barricaded inside a university.
Lord Alton, a member of the All Party Group on Freedom of Religion or Belief, said that the situation at the Hong Kong Polytechnic University was "critical".
He blamed "disproportionate" police brutality on the escalation of violence across the city, which has turned fatal in recent weeks, and said he feared further "bloodshed".
"Bloodshed must be avoided. I join calls to Hong Kong's Chief Executive Carrie Lam to take immediate action to prevent a tragedy," he said.
"I do not condone the violence on the part of some of the students, but equally it is important to understand that the disproportionate police brutality and cynical, manipulative, provocation by agents provocateurs is what has brought Hong Kong to this crisis point.
"I urge Hong Kong's authorities not to escalate the crisis further, but rather to de-escalate it and seek ways to address the protesters' grievances rather than respond to them with force."
The university campus was the scene of violent clashes between police and protesters last week. Hong Kong's Hospital Authority reports that 116 people have been injured in the stand-off and taken to hospital for treatment.
Some have been arrested as they attempted to leave the building, with police firing tear gas and rubber bullets at around a hundred protesters, the BBC reports.
On Sunday, the former Speaker of the House of Commons John Bercow said: "I have had the privilege of meeting several of the very brave pro-democracy activists, of different generations, from Hong Kong and am inspired by their courage and dignity.
"The erosion of freedoms in Hong Kong over recent years has spiralled out of control in recent months, and I join appeals to Carrie Lam to do her duty to protect the lives of Hong Kong citizens, especially young people, and prevent loss of life.
"I do not condone the violence on the part of a small minority of protesters, but I believe Hong Kong people have a right to live in freedom, with dignity, basic human rights and without fear, and for that reason I urge the Hong Kong government to order the police to exercise restraint."
Sir Malcolm Rifkind, the former Foreign Secretary and a patron of pro-democracy group Hong Kong Watch, said that Lam must order the police not to use live ammunition.
"Hong Kong's Chief Executive has the responsibility to do everything possible to prevent a massacre. She must order the police to exercise restraint and not to use live ammunition or other forms of lethal force," he said.
"A bloodbath on a Hong Kong campus would be devastating for Hong Kong as a whole. I also urge those students who have engaged in violence to stop. I condemn violence on all sides and I call on both sides to show restraint and pull back from the brink."
Hong Kong was a British colony until the handover to China in 1997. An agreement with the UK was reached before this time to ensure the protection of special freedoms for Hong Kong under the "one country, two systems" principle, but protesters fear the erosion of these liberties as Beijing seeks to tighten control of the territory.
The protests were triggered in June by legislation proposing that suspected Hong Kong criminals be extradited to the mainland for trial. Despite the withdrawal of the legislation, protests have continued and since evolved to include demands for an investigation into police brutality and the protection of democracy.