Protests in Kolkata against a controversial Indian citizenship law have continued into their second day. The new law entitles non-Muslim migrants from three Muslim-majority countries to citizenship if they are facing religious persecution. On Saturday, protesters blocked motorways and attacked trains and stations in West Bengal's capital. A curfew was also imposed in Guwahati, in the north-eastern state Assam, after two people died in clashes this week. The curfew was lifted from 09:00 local time (03:30 GMT) until 16:00 (10:30 GMT) on Saturday. Protest groups in Guwahati have said they plan to defy the curfew on Saturday evening. The UK, US and Canada have issued travel warnings for people visiting India's north-east, telling their citizens to "exercise caution" if travelling to the region. Smaller demonstrations have been breaking out across India. On Friday, hundreds of mostly-student protesters clashed with riot police in New Delhi, while demonstrators in Bengal set fire to buildings at a railway station. Other, smaller rallies were also held in the southern states of Kerala and Karnataka. Mamata Banerjee, West Bengal's chief minister, opposes the law and has said she will not implement it. She has also called for more rallies to be held next week. The chief ministers of Punjab, Kerala, Madhya Pradesh and Chhattisgarh have also said they will not implement the law.