A controversial Tunisian pro-Islamist militia said on Sunday police had released two of its officials arrested at a prohibited meeting.

On Saturday, police detained Imed Deghij and Mohamed Amine Agrebi, officials from the League for the Protection of the Revolution, and a handful of their supporters for several hours.

Prime Minister Ali Larayedh said on Thursday that Tunisia is making progress in its bid to dismantle "terrorist" cells despite the presence in the country of armed groups and recent clashes with Islamists.

"There is progress in dismantling the terrorist networks. We are confronted by small groups who practice terrorism and have links to terrorist parties," Larayedh told a news conference.

Ansar al-Sharia spokesman Seifeddine Rais, detained in the Tunisian city of Kairouan at the weekend as police enforced a government ban on its annual congress, was released on bail on Wednesday, the Salafist group said.

"God be praised, our brother Seifeddine Rais has been freed," the group said on its Facebook page.

Radical Salafist group Ansar al-Sharia, which Tunisian authorities have branded a terrorist organization, has called for a protest in the city of Kairouan on Friday against the arrest of its spokesman.

"Call to all Muslims to a protest in support of Ansar al-Sharia's spokesman Seifeddine Rais, in front of the headquarters of ruling Islamist party Ennahda near Bab Jalladine" in Kairouan, the group said on its Facebook page.

A 66-year-old Tunisian man has died from the new coronavirus following a visit to Saudi Arabia and two of his adult children were infected with it, the Tunisian Health Ministry reported.

His sons were treated and have since recovered but the rest of the family remains under medical observation, the ministry said in a statement Monday. The World Health Organization confirmed the cases of the children, but said one of them was a daughter who was with her father for part of the trip to Saudi Arabia and Qatar. There was no immediate way to reconcile the differing reports.

Clashes broke out between radical Islamists and police on Sunday after Salafist movement Ansar al-Sharia told its followers to gather "in large numbers" near Tunis for its annual congress, defying a government ban.

Hundreds of Salafists erected barricades in the streets of Ettadhamen, a poor neighborhood 15 kilometers (9 miles) west of Tunis, and hurled rocks at police who responded with tear gas, Agence France Presse reported.

Tunisian security forces deployed in strength on Saturday after Salafist movement Ansar al-Sharia called on its hardline Islamist supporters to defy a government ban on its annual congress.

There was a heavy police presence at tollbooths along the main highway from the capital to the central city of Kairouan where the Salafists have vowed to hold Sunday's gathering, Agence France Presse correspondents reported.

The Tunisian government has definitively banned hardline Salafist group Ansar al-Sharia from holding its annual congress at the weekend, the interior ministry announced on Friday.

"We have decided to prohibit this gathering, which would be in violation of the law and because of the threat it represents to public order," a statement said.

The Tunisian government will decide by Saturday whether to allow or ban Salafists from holding their annual congress, the interior minister said on Friday, warning however "death threats" from radical Islamists will not be tolerated.

"The final decision will be taken today or tomorrow," Lotfi Ben Jeddou told Kalima radio.

Tunisia's hardline Salafist movement Ansar al-Sharia vowed on Thursday to go ahead with its annual congress at the weekend in defiance of a government ban on the controversial gathering.

"We are not asking permission from the government to preach the word of God and we warn against any police intervention to prevent the congress from taking place," spokesman Seifeddine Rais told a news conference in Tunis.