GAUHATI, India (AP) — Senior citizens in India’s northeastern Assam state have protested against a new citizenship law passed by Prime Minister Narendra Modi’s government that excludes Muslims.

About 1,500 senior citizens held a protest in the state capital, Gauhati, on Monday. Protests in the state against the law have spread across the country, claiming at least 23 lives.

“Until our last drop of blood, we will not allow them to implement it,” said Gajendra Nath Pathak, 81, who joined the senior citizens’ protest.

Bina Bora, 70, said she couldn’t sit at home while other people were protesting the law. “Why is the government forcefully implementing such a law, which will destroy unity,” she asked.

The new Citizenship Amendment Act allows Hindus, Christians and other religious minorities who are in India illegally to become citizens if they can show they were persecuted because of their religion in Muslim-majority Bangladesh, Pakistan and Afghanistan. It does not apply to Muslims.

Thousands of people have protested in Assam in the past week, setting up blockades and disrupting traffic and business. At least five people were killed in the state when police fired to quell the demonstrations.

Assam was the site of an earlier government program to create an official list of citizens to weed out foreigners living in the state illegally. About 2 million people were excluded from list, about half Hindu and half Muslim, and have been asked to prove their citizenship or else be considered foreign.

Opposition parties say the Citizenship Amendment Act could provide a fast track to naturalization for many of the Hindus left off Assam’s citizenship list, while explicitly leaving out Muslims.