From campuses along India’s Himalayan northern border to its southern Malabar Coast, a student-led protest movement against a new law that grants citizenship on the basis of religion spread nationwide on Wednesday despite efforts by the government to contain it.

The law provides a path to citizenship for Hindus, Buddhists, Christians and other religious minorities who are in India illegally but can demonstrate religious persecution in Muslim-majority Bangladesh, Pakistan and Afghanistan. It does not apply to Muslims.

Critics say it’s the latest effort by Prime Minister Narendra Modi’s Hindu nationalist-led government to marginalize India’s 200 million Muslims, and a violation of the country’s secular constitution.

Modi has defended it as a humanitarian gesture, but on Wednesday, authorities tightened restrictions on protesters, expanding a block on the internet and a curfew in Assam, where protests since the law’s passage a week ago have disrupted life in Gauhati, the state capital. They also restricted assembly in a Muslim neighborhood in New Delhi where demonstrators on Tuesday burned a police booth and several vehicles.

After India’s Supreme Court postponed hearing challenges to the law Wednesday, huge demonstrations erupted in Gauhati, in Chennai, in the southern state of Tamil Nadu, and in Mumbai, India’s financial capital. Protesters also rallied in Srinagar, the main city in disputed Kashmir and in the tourist mecca of Jaipur in the desert state of Rajasthan, and threw stones at buses in Kochi, the capital of the southernmost state of Kerala.