Tunisian authorities say the moderate Islamist Ennahdha party has won the country's first free elections, taking 90 of 217 assembly seats – three times the number won by its nearest rival.

Ennahdha secured more than 41 percent of the vote and will dominate Tunisia's constituent assembly, tasked with writing a new constitution, appointing a president and forming a caretaker government.

The center-left Congress for the Republic , a secular party founded by noted human rights activist Moncef Marzouki, placed second with 30 seats. The third-place Democratic Forum for Labor and Liberties, or Ettakatol, won 21.

The two liberal groups have already begun talks on forming an interim unity government with Ennahdha, which was banned for decades.

Late Thursday, violent protests broke out in the provincial town of Sidi Bouzid when hundreds of young people marched on Ennahdha's local headquarters after election officials invalidated the seats won by the rival Popular List party.

The town is the birthplace of the popular uprising that ousted longtime President Zine el Abidine Ben Ali and ignited the Arab Spring protests that have transformed the region.

Ennahdha officials say the group intends to propose its secretary general, Hamadi Jebali, as the next head of Tunisia's government.

The party's candidates have cited as a model the secular, pluralist democracy in Turkey, where the ruling party also has an Islamist identity.

Election observers predict that women could capture nearly one-third of the seats in the constituent assembly, a far larger proportion than in any Arab country.

Tunisia's landmark election was widely considered free and fair. Sunday's vote came a little more than nine months after Tunisians overthrew Mr. Ben Ali.