COLOMBO, Sri Lanka — The new president, Maithripala Sirisena, was sworn into office Friday and vowed to curtail the powers amassed by his predecessor, who was swept aside in a stunning election upset.
Sirisena, a longtime political insider, and an ally of former President Mahinda Rajapaksa until just a few weeks ago, won the Thursday election by capitalizing on Rajapaksa’s unpopularity among the island nation’s ethnic and religious minorities, as well as grumbling among the Sinhalese majority about his family’s growing power.
‘‘With this victory we will implement the 100-day program in our election manifesto,’’ Sirisena told jubilant crowds after his swearing-in. Sirisena had promised to change Sri Lanka’s Constitution to drastically reduce the power of the president and return the country to a parliamentary system with a prime minister as its leader.
Sirisena also promised that he would not run again for president.
He thanked Rajapaksa for conceding defeat but called for future campaigns to be ‘‘much more mature,’’ and blasted the state media for its coverage.
He took the oath of office with senior Supreme Court Justice Kanagasabapathy Sripavan, bypassing the country’s chief justice, who was installed by Rajapaksa in a widely criticized move to expand his authority even more.