Associate professor Khalid Hameed was allegedly killed by his student who, according to the police report, had warned the teacher against holding mixed gender reception because it is "against the teachings of Islam."
A Pakistani student was arrested on Wednesday after stabbing his professor to death for organising a mixed-gender reception at a government college, police said.
Associate professor Khalid Hameed was killed on the campus of Sadiq Egerton College in the southern city of Bahawalpur, a local police official told AFP news agency.
"The professor had organised a gender mix reception for the new students and the event was supposed to take place tomorrow, on Thursday," he said.
According to the report registered with the police, a copy of which was seen by AFP, the student had shouted that he killed the professor because he was "spreading obscenity."
"The gender mix reception is against the teachings of Islam and I had warned him to stop it," he was quoted as saying in the report filed with the police.
The professor's son Waleed Khan, who was with him at the time of the incident, said the student was waiting for his father.
"As my father was about to step into his office, the guy attacked him with a knife, hitting him at his head and stomach," he told AFP.
"My father then fell down and I rushed to him, the student held his knife and started shouting 'I have killed him, I had told him that a gender mix reception is against Islam'," he said.
"We took him to hospital, but he had already died," he said.
He said the student dropped his knife and the guards arrested him.
The Punjab provincial government said on Twitter that the student had been arrested and the chief minister had sought a report from the police.
Mixed-gender events are not uncommon in Pakistan's educational institutions but they come with more restrictions in government-owned colleges than in private ones.
Recently, a government university in Punjab issued a dress code barring female students from wearing tops with a deep neckline, sleeveless shirts, tights, skinny jeans or capri pants.
In many government universities there is a restriction on students sitting as "couples" and "inappropriate" interaction between male and female students.