Sri Lanka's prime minister resigned on Monday, hours after clashes between pro- and anti-government demonstrators in the commercial capital Colombo amid the country's worst economic crisis, which has spurred protests by thousands.

During weeks of unprecedented demonstrations, protesters across the island nation of 22 million people have demanded that President Gotabaya Rajapaksa and his elder brother, Prime Minister Mahinda Rajapaksa, quit for mishandling the economy.

In a statement, the prime minister's office said the 76-year-old veteran politician had resigned.