Some 200 lawyers in their traditional black suits descended upon the Punjab Institute of Cardiology (PIC), destroying windows and doors and setting a police van on fire.

Doctors and nurses fled, leaving intensive care patients unattended.

“Three patients including an elderly woman died after doctors failed to provide them timely treatment and remained engaged in averting the assault,” Punjab provincial health minister Yasmeen Rashid said.

Kamran Ali, a Lahore government official, told Reuters that the lawyers attacked the hospital because of an earlier incident in which a doctor beat a lawyer at the hospital after he refused to queue with patients.

In particular, they were angry that the doctors filmed the incident and shared it on social media.

“This was kind of a high-handedness which none of civilised societies can tolerate,” provincial law minister Raja Basharat told AFP.

“Several lawyers have been identified from the television footage and the government will deal with all those involved in the attack with an iron hand,” Mr Basharat said.

Prime Minister Imran Khan’s office has launched an investigation.