The Tunisian town that was the birthplace of the Arab Spring uprisings has once again been rocked by violent demonstrations.

Protests erupted Friday against Tunisia's newly elected Ennahda party in the central city of Sidi Bouzid. Media reports say security forces fired shots into the air and tear gas at demonstrators who tried to raid the party's headquarters.

Later Friday, the government imposed a curfew in the city, 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.

The latest unrest came as the Islamist Ennahda party began talks with rival parties on forming a coalition government, a day after winning the most seats in the country's first free elections.

Ennahda leader Rachid Ghannouchi called for calm and said his party would work to form a new government in “friendliness” and “brotherhood.”

The protests began after election officials invalidated seats won by the rival Popular List party, citing campaign violations.

Election officials announced the final results on Thursday, four days after Tunisians voted. The Ennahda party took 90 of 217 assembly seats, three times the number won by its nearest rival.

Ennahda secured more than 41 percent of the vote and will dominate the constituent assembly. The assembly has been tasked with writing a new constitution, appointing a president and forming a caretaker government.

The center-left Congress for the Republic , a secular party, placed second with 30 seats. The Democratic Forum for Labor and Liberties — or Ettakatol — came in third with 21 seats.

Those two liberal parties have launched negotiations with Ennahda, which had been banned for decades under the previous government.

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.