India's Supreme Court declined calls to suspend the implementation of a new citizenship law on Wednesday, deciding that a constitutional bench of five judges was needed to hear all the challenges to legislation that critics point out discriminates against Muslims.

The court gave Prime Minister Narendra Modi's government four weeks to respond to 144 petitions challenging the constitutional validity of the law which has ignited protests across the country.

The law, which came into effect on Jan.10 after being passed by parliament in December, lays out a path for citizenship for six religious minorities in neighbouring mostly-Muslim countries - Pakistan, Afghanistan and Bangladesh.