Two murder suspects and a legal clerk were gunned down in a lawyer's chambers in a court in Pakpattan on Monday.

Four people were in the chambers of Advocate Shaukat Wattoo where hearing of a murder case was underway, police spokesman Muhammad Asif said.

Two brothers nominated in the murder case, Ibrahim and Ifrahim Malkana, had arrived for a hearing to secure interim bail. Asif said, adding that the brothers, along with Wattoo's clerk, were shot dead while one man was injured in the shooting and shifted to a hospital for treatment.

The incident sparked panic across the court premises, with people fleeing the building fearing an attack.

Police have imposed a curfew in the city and are searching for the shooters. Samples of blood and shells of bullets recovered from the crime scene have been sent to Lahore for forensic tests and bodies of the victims are being shifted to District Headquarters Hospital for a post-mortem examination, the spokesperson said.

A first information report will be filed when a complainant comes forward to lodge a case, police said.

Lahore High Court Chief Justice Sardar Mohammad Shamim Khan took an administrative notice of the incident. He directed the district and sessions judge to file a report within 24 hours. Justice Khan also directed the provincial police chief to complete the probe into the matter as soon as possible and arrest the culprits.

Punjab Chief Minister Usman Buzdar took notice of the incident and ordered a detailed report on the incident.

Following the incident, lawyers in Pakpattan staged a protest against the killing of the legal clerk. The district bar council President Rao Anwar said that the legal fraternity of Pakpattan was "weary with grief" and announced three days of mourning.