TUNIS, Tunisia - Major gunbattles erupted outside the palace of Tunisia's deposed president, in the center of the capital, in front of the main opposition party headquarters and elsewhere on Sunday as authorities struggled to restore order.

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Police arrested dozens of people, including the top presidential security chief, as tensions appeared to mount between Tunisians buoyant over Zine El Abidine Ben Ali's departure and loyalists in danger of losing major perks.

There were cheers and smiles in much of Tunis, the capital, as residents tore down the massive portraits of Ben Ali, some of them several stories high, that hung from lampposts and billboards and were omnipresent during his 23-year reign.

Prime Minister Mohamed Ghannouchi said on state TV that a new national unity government will "most certainly" be announced Monday "to open a new page in the history of Tunisia."

There are three legal opposition parties that could be included in the government Ghannouchi has been directed to form by the interim president, Fouad Mebazaa. Negotiations are advanced, Ghannouchi said Sunday night.

Worries among Tunisians, however, grew with the violence and worsening shortages of essentials such as milk, bread and fresh fish.

"We're starting to feel it now," said Imed Jaound at the Tunis port, which has been closed since Friday, when Ben Ali fled to Saudi Arabia.

A gunbattle broke out around the presidential palace late Sunday afternoon in Carthage on the Mediterranean shore, about 15 kilometers (10 miles) north of Tunis. The army and members of the newly appointed presidential guard fought off attacks from militias loyal to Ben Ali, said a member of the new presidential guard. Helicopters were surveying the zone.

The militias emerged from a forest to charge, the guard member said by telephone. He told The Associated Press the militia are "numerous" and are using various kinds of arms but gave no further details. He spoke on condition of anonymity because he was not authorized to be publicly named.

Residents of Carthage - a center of power in ancient times but now a Tunis suburb popular with tourists - said they have barricaded themselves inside their homes amid the shooting. Many soldiers were in the palace, but it was unclear whether any of the interim government's leaders were.

One Carthage resident said she saw four men in a taxi speed through a military checkpoint at the end of her street and toward the palace nearby. Soldiers shot at the taxi and the men inside returned fire.

The resident, who asked not to be named because of security concerns, said her neighbors saw other armed men break through checkpoints in civilian cars. The gunbattle lasted about four hours before calm returned in the evening, she said.

Other gunfights broke out near the PDP opposition party headquarters and a two-hour-long gunbattle raged behind the Interior Ministry, long feared during Ben Ali's reign as a torture site. Residents of the city center heard constant volleys of gunfire throughout much of the afternoon; they were ordered to stay away from windows and keep their curtains closed.

The prime minister said Sunday night that police and the army have arrested numerous members of armed groups, without saying how many.

"The coming days will show who is behind them," Ghannouchi said. He added that arms and documents have been seized from those arrested.

"We won't be tolerant towards these people," the prime minister said.

The security chief, Ali Seriati, and his deputy were charged with a plot against state security, aggressive acts and for "provoking disorder, murder and pillaging," the TAP state news agency reported.

Police stopped vehicles as the city remained under a state of emergency. More than 50 people were arrested on suspicion of using ambulances, rental cars and government vehicles for random shootings, a police official told The Associated Press. A crowd of 200 in Tunis cheered one such arrest Sunday.

Before the gunbattle at the opposition party headquarters, police arrested a group of nine Swedish boar hunters traveling in taxis toward a nearby hotel after their flight home was canceled, one of the Swedes, Ove Oberg, said. Police roughed the men up and accused them of being terrorists, Oberg said, recounting his ordeal before a group of journalists.

"When they saw this gun, they went crazy," he said, referring to a hunting rifle in the trunk of the taxi.

Six of the men were released, some with their clothes stained with blood, while three others remained in police custody Sunday evening.

Dozens of people have died in a month of clashes that were initially between police and protesters angry about repression and corruption but now appear to be between police and Ben Ali loyalists.

A Paris-based photojournalist, Loucas Mebrouk von Zabiensky, 32, of the EPA photo agency, was in critical condition after being hit in the face Friday with a tear gas canister, according to a French consular official in Tunisia. The official, speaking on condition of anonymity because of embassy rules, did not provide other details or an explanation of an earlier announcement that the photographer had died.

Mebazaa, a former parliament speaker who was sworn in as interim president Sunday, has told Ghannouchi to create a national unity government and urged him to consult with the opposition, who were marginalized under Ben Ali. Presidential elections are to be held in 60 days.

The downfall of the 74-year-old Ben Ali, who had taken power in a bloodless coup in 1987, served as a warning to other autocratic leaders in the Arab world. His Mediterranean nation, a popular tourist destination known for its wide beaches, deserts and ancient ruins, had seemed more stable than many in the region before the uprising that began last month. Hundreds of stranded tourists were still being evacuated from the country Sunday.

Tunisia's foreign minister will brief Arab leaders meeting in Egypt this week on the upheaval surrounding Ben Ali's ouster.

In Israel, Prime Minister Benjamin Netanyahu told his Cabinet that the unrest in Tunisia illustrated the widespread instability plaguing the region and underscored the need for strong security arrangements in any future peace deal with the Palestinians.

Many Tunisians were especially overjoyed at the prospect of life without Ben Ali's wife Leila Trabelsi and her family.

Leaked US diplomatic cables released by WikiLeaks had discussed the high levels of nepotism and corruption displayed by Trabelsi's clan. But US State Department spokesman P.J. Crowley rejected any notion that WikiLeaks disclosures led to the revolution in Tunisia, saying Sunday that Tunisians were already well aware of the graft, nepotism and lavish lifestyles of the former president and his relatives.

Tunisian media reported one brother-in-law of the president, Imed Trabelsi, was attacked by an angry mob at Tunis airport and died. The reports could not be immediately confirmed.

Ordinary Tunisians concentrated on two key needs Sunday - food and security.

Many scoured the capital for food as calm returned to some residential areas. Most shops remained closed Sunday, others were looted and bread and milk were running short.

Fish mongers were selling two- or three-day-old fish, said Ezzedine Gaesmi, a salesman at the indoor market in Tunis, where many stands were empty.

"There's no fresh fish. If it continues for two or three more days, we'll close," he said.

Overnight citizen patrols armed with bats, sticks and golf clubs were being organized in both wealthy and working-class neighborhoods. Fatma Belaid stayed up late to serve rounds of coffee to patrols in her section of Tunis.

"Everyone participates as he can," she said.