Tehran: Iranian students clashed with security forces at universities across Iran on Sunday, according to the country's activist and human rights groups.

Sunday's violence came as nationwide protests gripped the country despite threats from the country's paramilitary Revolutionary Guard, reported CNN.

The Guard's chief, Hossein Salami had warned young Iranians that Saturday would be the last day of the protests first sparked by the September 16 death of Mahsa Amini in the custody of the country's morality police.

On Saturday Salami called on Iranian young people specifically to desist from protesting, reported CNN.

"Today is the last day of the riots. Do not come to the streets again. What do you want from this nation?" Salami said.

In a video obtained by CNN via the pro-reform activist outlet Iran Wire, two uniformed officers can be seen in what appears to be an attempt to arrest a protester. The video is said to be recorded at Sanandaj Technical College in northwestern Iran.

In the capital Tehran, activist groups claimed clashes broke out between protesters, members of the Basij militia and police officers in plain clothes at Azad University but CNN cannot independently verify whether those in the clashes are security forces.

Protests have swept through the Islamic Republic for weeks following the death of 22-year-old Mahsa Amini, who died on September 16 after being detained by "morality police" and taken to a "re-education centre," allegedly for not abiding by the country's conservative dress code.

In a video posted by activist group 1500 tasvir, a large crowd of protesters can be seen, with some holding sticks. Tear gas appears to be thrown across the crowd but it's unclear who it is thrown by.

In another video obtained by CNN via the pro-reform activist outlet IranWire, students at another university in the capital, the University of Tehran can be seen marching and chanting: "It's not the time for mourning. It's time for anger."

Official state news agency IRNA reported a "large gathering" of students and professors at the University of Tehran "in response to the recent events and terrorist attack on the shrine of "Shahcheragh," which took place in the southern city of Shiraz on Wednesday.

Also, in Sanandaj, gunshots can be heard in a video posted by Kurdish rights group Hengaw, said to be recorded near the University of Kurdistan.

Activist group 1500 Tasvir also posted a video showing security forces outside another educational facility in the province, the Sanandaj Technical College for Girls on Sunday.

Iran Human Right (IHRNGO), an NGO based in Norway, condemned "the encroachment of university campuses by armed plainclothes forces and the violent crackdown on peaceful student protests," in a statement Sunday.

"With the continuation of nationwide protests, Islamic Republic armed plainclothes forces have entered university campuses to violently crush and arrest protesting students," IHRNGO said.

IHRNGO Director and University of Oslo Professor, Mahmoud Amiry-Moghaddam, called on "universities and academic institutions around the world to support student demands and condemn the outrageous violation of university campuses by Islamic Republic forces."