COLOMBO (AFP/Reuters) - Sri Lankas Supreme Court agreed Friday to hear a challenge to the arrest of defeated presidential candidate Sarath Fonseka, as Opposition parties stepped up a campaign for his immediate release. The court accepted a petition by Fonsekas wife requesting that his arrest be ruled illegal, and ordered the state to allow the former army chief family visits and medicines. The court granted leave to proceed with the case because it appeared, on the face of it, there had been a breach of fundamental rights of General Fonseka, a court official told AFP. The court was scheduled to reconvene on February 23. Fonseka was arrested on Monday, two weeks after being trounced in presidential elections by the incumbent, President Mahinda Rajapakse. His detention triggered violent protests in Colombo and other parts of Sri Lanka. The Defence Ministry says he is to be court-martialled on unspecified charges of conspiring against the government. A lawyer for Fonseka said they regarded the Supreme Court decision to take up the petition as a major victory. Hundreds of Fonseka supporters packed the courtroom, while police manned barricades outside. Anti-riot squads had been put on alert after violent clashes Wednesday outside the court complex between Fonseka loyalists and ruling-party activists. Members of the elite Special Task Force commandos were also deployed in the city. Hundreds of lawyers marched outside the court after the hearing carrying placards demanding Fonsekas release. The black-robed lawyers marched out of the Supreme Court building towards a nearby street intersection where eight people were injured when clashes broke out between supporters of Fonseka and the government earlier in the week. Release Sanath Fonseka soon, a banner carried by the lawyers, said. The islands influential Buddhist clergy responded to the spreading anti-government protests and said they planned a meeting next week to agree on a collective move to press the government to defuse tensions. Serious doubts have been raised in the country about democracy and good governance and we as the Buddhist clergy are concerned about it, the countrys topmost monks said in a joint statement. We cannot afford to remain silent. We wish to have a meeting of all leading Buddhist monks to decide on a course of action on February 18, they said. As the court proceedings got underway in Colombo, the parliamentary Opposition Leader and former premier Ranil Wickremesinghe met President Rajapakse to push for the former army chiefs freedom. He also insisted on being allowed to meet Fonseka, who is detained at the navy headquarters in Colombo. Fonsekas wife says her husband needs medicines on a regular basis for the injuries he received in an April 2006 suicide bomb attack blamed on Tamil Tiger rebels.