At least seven people, including four children, were killed in a fire that broke out in their house on Sunday, police officials said.
The blaze erupted at a house in the Ali Pur area of Muzaffargarh district, located some 380 kilometres (236 miles) from the provincial capital, Lahore.
District Police Officer (DPO) Hassan Iqbal said police were investigating the incident, adding that all details of the case will be disclosed soon.
Rescue service chief Dr Hussain Mian said firefighters retrieved the charred bodies of a 65-year-old man, two women aged 35 and 19, three boys aged 3, 10 and 12 and a 2-month-old infant.
Dr Mian said the bodies had been sent for autopsy and forensic examination.
Meanwhile, Punjab Chief Minister Usman Buzdar, in a statement, expressed heartfelt grief on the loss of lives in the incident.
He ordered an inquiry into the blaze "from every aspect" and also sought a report of the incident.
Case registered against two suspects
Later in the day, a case was registered at the Civil Lines Police Station against two suspects on charges of burning to death seven people.
The case was registered on the complaint of Mehmood, a brother of one of the deceased persons.
"I was in Multan for business. When I returned and was near my home, I saw it in flames. While two men Manzoor Hussain and Sabir Hussain were also seen fleeing the spot," he told police in a statement.
Regarding the possible motive, Mehmood said that he had married a woman named Fouzia Bibi out of free will, alleging that his father-in-law and brother-in-law were unhappy with the marriage and they set his home ablaze "in rage".
Police said the cause of the fire was being investigated, adding that officials were trying to ascertain why none of the family members woke up when the fire erupted.