Tunisia's moderate Islamist leaders are under pressure from a radical Muslim fringe, forcing them to stress their liberal democratic credentials without alienating their base, analysts say. Ultra-conservative Salafists have in past months launched bold challenges -- demanding full-face veils for female university students, castigating a TV channel for a "blasphemous" film and beating up journalists at a protest. Their actions have heightened tensions in the north African country that was under secular rule for decades until the overthrow a year ago of strongman Zine El Abidine Ben Ali kicked off the Arab Spring and led to elections in October. Moderate Islamist Prime Minister Hamadi Jebali, who took power in December, has this week adopted a firmer tone, while his Ennahda party also took unusually clear positions against the extremist religious activists. On Tuesday, the authorities intervened to end a two months old sit-in protest by Salafists on a university campus, the faculty of letters at Manouba, about 25 kilometres (15 miles) from the capital Tunis. The students, most of whom were not enrolled at the university, had camped out there since November to demand the right for women students to wear the full veil, known as the niqab, and for a place of prayer on campus. Police removed them on the first day of delayed exams. The university had banned the niqab citing security concerns if students wore it with a flowing garment, which would conceal them from head to toe. Also this week, Ennahda in an unprecedented statement affirmed its commitment to free expression and dissociated itself from a legal action lawyers close to Islamist groups launched against the privately-owned Nessma satellite TV station. The religious protesters were outraged, and the station was attacked, after it screened the animated French-Iranian film "Persepolis" in which god is shown as a white-bearded man. Islam forbids depictions of religious figures. Nessma TV director Nabil Karoui, whose house was attacked by protesters, is due to go on trial in April on morality charges for airing the movie. In previous hearings, his supporters were assaulted outside the court. The prime minister in a speech to the national assembly this week stressed his determination "to enforce the law" and denounced the beatings of journalists. "The government is worried," said Ali Laidi Ben Mansour, editor in chief of Nessma and of news site webmanagercenter. "From my point of view, a confrontation is looming between the 'moderate Islamists' of Ennahda and the radical Salafists. "Until now the Salafists -- who are certainly a minority but capable of mobilizing and acting -- have taken advantage of the government's hesitation." He said Ennahda has no deep interest in facing up to this problem, which highlights that the party itself is "torn between hawks and doves". The Salafists have a hard core of about 200 people but 5,000-7,000 supporters, including backers of Ben Ali's dissolved party, according to estimates. "The fact remains that much of the base for Ennahda is close to that doctrine," said researcher Alaya Allani, specialist in Islamic movements in North Africa. Suddenly, Tunisia's ruling Islamist party "finds itself in a very difficult situation," said the researcher. "It does not want go to war with the Salafists, because it does not want to lose that base before the next election. "But it won't be able to maintain its stance of ambiguity much longer." The party's "balancing act" won't be able to continue for long, argued the site Businessnews.com.tn on Wednesday. Slah Ourimi, a lawyer with the Tunisian League for Human Rights, said the signals the government and Ennahda are sending are still "too timid" while the extreme right was "launching trial balloons and "testing" Tunisian society. "Students being assaulted, journalists beaten, exams disrupted -- what is happening is very serious and very dangerous," Ourimi said. "The government has taken small steps in recent days. But we want a clear, determined position and that the government stands up completely to these radical groups that are against the republic and against democracy."