Tunis: A Tunisian Islamist party has emerged victorious in the Arab Spring's first elections, taking 41.47 percent of votes cast nine months after the ouster of dictator Zine el Abidine Ben Ali.

Violent protests broke out in the central town of Sidi Bouzid, where the uprising started last December, after the provisional final results were announced, witnesses and the interior ministry said on Thursday.

The Ennahda party obtained 90 seats in a new 217-member assembly that will rewrite the constitution, appoint a president and form a caretaker government, elections chief Kamel Jendoubi told journalists in Tunis.

He also announced the invalidation of six candidates' lists of the Petition for Justice and Development, including one in Sidi Bouzid, notably due to "financial irregularities".

The group had nevertheless obtained 19 assembly seats.

Witnesses said more than 2,000 young people marched on Ennahda's headquarters in Sidi Bouzid at the news and pelted security forces with stones.

According to sources, they broke doors and windows of the Ennahda building and set alight tyres on the town's main road.

A similar protest was under way in the town of Regueb, some 50 kilometres (30 miles) from Sidi Bouzid, said witnesses, where a gunshot was fired at the local Ennahda offices.

On the main road in the capital Tunis however, the results were met with a cacophony of car hooters blaring, as people hung out of car windows singing and waving Ennahda and Tunisian flags.

The provisional results put two leftist parties in second and third place after Sunday's historic polls: the Congress for the Republic (CPR) obtaining 13.82 percent of the vote, representing 30 seats; and Ettakatol, with 9.68 percent or 21 seats.

In fourth place was the Petition, a grouping led by Hechmi Haamdi, a rich London-based businessman said to have close ties to Ben Ali. Following the announcement of the invalidations, Haamdi announced the withdrawal of all his candidates from the assembly.
Ennahda was banned under Ben Ali's regime and only registered as a political party in March.

But on Wednesday, preempting the official news of its victory, it announced it had started coalition negotiations and intended to form a new government within a month.

The party, which presents itself as having a moderate Islamist agenda, has put forward its number two, Hamadi Jebali, as candidate for prime minister.