Students of Jamia Millia Islamia University in Delhi on Friday clashed with police as protests against the amendments made to the Citizenship Act turned violent, PTI reported. At least 50 protestors were detained, according to NDTV. Officials have also banned large gatherings in the area.

Hundreds of students had gathered for a march to Parliament House from the university campus to voice their opposition to the legislation. Visuals showed police use tear gas and batons to disperse the students. Reports said a few protestors were injured in the clash.

“We were marching peacefully when the police stopped us,” a student told PTI. “Then they lathi-charged us in an attempt to make us retreat.” But a police officer at the area claimed that the protestors had attacked first.

The Delhi Metro Rail Corporation closed the Patel Chowk and Janpath stations for a brief period of time due to protests. They were opened about an hour later.

The contentious amendment allows citizenship to persecuted people of six communities – but not Muslims – from Bangladesh, Pakistan and Afghanistan, provided they have resided in India for six years. The cut-off date is December 31, 2014. The amendments were approved by both Houses of Parliament this week and were signed into law by President Ram Nath Kovind on Thursday night.

Two people were killed in Assam and 21 were injured as demands to withdraw the changes to the 1955 law were raised. The widespread fear in the North East is that populations defined as indigenous to the region will be culturally and physically overrun by migrants as a result of these changes.