One person was killed and two injured on Sunday in a shooting outside government offices in the Sri Lankan capital Colombo, amid political tensions after the president dismissed and swiftly replaced the prime minister, according to police.

The shooting incident took place as Arjuna Ranatunga, Sri Lanka's petroleum minister under ousted Prime Minister Ranil Wickremesinghe, tried to enter his ministerial offices which were at the time surrounded by supporters of Mahinda Rajapaksa, a former president and the newly-installed prime minister, police spokesperson Ruwan Gunasekara told EFE.

Three people were injured and taken to the hospital, one of whom died of gunshot wounds, the chief nurse at the National Hospital of Sri Lanka, Pushpa Ramyani, told EFE.

As President Maithripala Sirisena gave an address live to the nation, the former cabinet minister's bodyguards fired off several shots during clashes between opposing supporters, according to the police spokesperson.

This was the first case of violence on the island since Sirisena named Rajapaksa as prime minister on Friday, then suspended parliament until mid-November the following day.

Sirisena justified his decision to oust Wickremesinghe on Sunday, saying he dismissed him over his "arrogant" behavior.

Wickremesinghe has meanwhile refused to leave his official residence, while India, the United States and several countries in the European Union have expressed their concern over the events.