Former Defence Secretary Gotabhaya Rajapaksa has congratulated his brother, Mahinda Rajapaksa, on his appointment as the new Prime Minister of Sri Lanka.

"My warmest congratulations to the new Prime Minister Hon Mahinda Rajapaksa," Rajapaksa tweeted, a short while ago. 

"Now together, we can rebuild a stable and progressive new Sri Lanka," he also said.  

Many Joint Opposition Parliamentarians also shared congratulatory messages following the appointment of Rajapaksa.

Meanwhile, the Army has been deployed to beef up security at all state media institutions, Asian Mirror learns. 

Sources said security had been tightened following reports that some ITN employees had been assaulted by unruly groups.