FREETOWN, April 5 (Xinhua) -- Opposition candidate and former military junta leader Julius Maada Bio of the Sierra Leone People's Party (SLPP) was sworn in as Sierra Leone new president on Wednesday night.

According to the 1991 constitution of the country, immediately after the National Electoral Commission (NEC) announces the winner of the election, the president-elect should take the oath of office.

Maada Bio, in traditional white robes, was sworn in at a hotel in the capital Freetown before midnight.

In a speech after the swearing-in ceremony, Maada Bio said "Today is a new dawn for the country," adding that he would pursue national cohesion and disciplined leadership.

Maada Bio won a narrow victory with 51.81 percent of more than 2.5 million valid ballots, while his main challenger, Samura Kamara, of the ruling All People's Congress (APC) garnered 48.19 percent, according to official results released by the commission.

This is the fourth election the West African country has conducted since the 11-year rebel war that ravaged the country was declared over in 2002. Sixteen political parties contested in the election, with more than 3.1 million voters registered across the country.

Maada Bio, 53, was the military head of Sierra Leone in 1996 under the National Provisional Ruling Council.

He was the SLPP presidential candidate in the 2012 election but defeated by his predecessor Ernest Bai Koroma of the ruling APC party.??