It is for the Subang Jaya police, not Universiti Putra Malaysia (UPM), to investigate recent allegations of harassment on campus, said a student support group.

Solidariti Mahasiswa Malaysia (SMM) secretary Kong We Cheng said the group disagrees with the police decision to leave investigations to campus authorities as "these are serious criminal cases involving extreme violence".

"We believe that the university authorities will not be able to conduct a fair investigation because they are involved in the cases," he said at a press conference on Friday.

He cited instances of the university's security personnel acting "unprofessionally" by watching the incidents without acting against the perpetrators.

"We urge the Subang Jaya district police to investigate the cases, and not leave these to the university," he said.

Members of anti-establishment student group Student Progressive Front (SPF) claimed they had been physically assaulted by members of the Aspirasi (pro-establishment) group while conducting an activity to assist new students on July 17.

SPF members alleged similar harassment on July 11 while conducting another activity, although this did not involve assault.

Gabungan Mahasiswa Islam president Mohd Haniff Baderun and Jaringan Rakyat Tertindas (Jerit) member Nalini Devi, who were at the press conference, denounced the alleged violence.

Kong said a protest letter had been sent to the higher education ministry, calling for action. This was signed by SMM, Jerit, Malaysian Youth and Democratic Movement and human rights group Suaram.

"We are going to submit another letter to Suhakam (Human Rights Commission of Malaysia) because the cases also relate to human rights," he added.

Higher Education Minister Mustapa Mohamed has urged UPM to investigate the complaints and to submit a report on the findings.