CAIRO (Update 3) - Thousands of Salafist protesters Friday packed Cairo's iconic Tahrir Square, where they joined members of liberal groups in a Friday of Unity to renew their calls for the trial of officials from the former regime. However, the Islamic slogans and banners showed potential tensions between the Salafists and the liberals. The Salafists, in a show of force, called for setting up an Islamic state and enforcing Sharia law in Egypt. Chanting "There is no God but Allah" and "Islamiya, Islamiya", the Salafists waved banners that read “Islamic Egypt”. They also waved Saudi flags. The Salafists' chants drew criticisms from others who said the slogans violated an agreement to avoid divisive issues. Instead of "Peaceful, peaceful," which demonstrators have chanted during confrontations with security forces, they repeated "Islamic, Islamic". And instead of "The people want to topple the regime", they yelled, "The people want to implement Sharia," a strict form of Islamic law. Salafists are ultraconservatives, close to Saudi Arabia's Wahhabi interpretation of Islam and more radical than the Brotherhood. They seek to emulate the austerity of Islam's early days and oppose a wide range of practices like intermingling of the sexes that they view as "un-Islamic". Many also reject all forms of Western cultural influence. More than 15 parties and political movements took part in yesterday's protest to demand an end to military trials of civilians, the prosecution of former regime members found guilty of abuse, and the redistribution of wealth. The Islamists wanted the Supreme Council of the Armed Forces (SCAF) to cease its plans for presenting a set of principles that will form a framework for a new constitution. Islamist groups such as the Muslim Brotherhood, Gamaa Islamiya and Salafists argued that only God's word is greater than any man-made constitution and that only a parliament chosen by free election can set the terms for a constitution, due to be re-written after the People's Assembly and the Shura Council will be elected in November. "Islamic law above the Constitution," the Salafists chanted. They said that they would gain enough support to dominate such a parliament and thereby set the terms. The groups fear that a kind of bill of rights could close off the possibility of a state run by Islamic laws. The liberal youths, who once dominated Tahrir, were a minority in the square. The protesters said tensions mostly emerged between liberal groups and Salafists rather than the Brotherhood, which takes a conservative but not strict Salafist approach to Islam. In Suez, some 120km northeast of Cairo, the official MENA news agency said some groups including the liberal Wafd Party announced they were withdrawing from the rally because of Islamist tactics. "(Wafd) and a large number of parties as well as the Suez Revolutionary Coalition decided not to participate after they had become sure that the religious groups participating refused the principle of harmony and insisted on slogans that bring up divisions," Ali Amin of the Wafd Party was quoted as saying. However, alongside the Islamic slogans, there were also other chants in Tahrir, such as "People and the Army, hand in hand". Some protesters have accused the Brotherhood, which was banned under Mubarak but now enjoys unprecedented freedom, of making a pact with the Army. The group denies it. But the question of how hard to push the Army over reforms remains. In the Sinai city of el-Arish, hard-line Salafists fired rocket-propelled grenades and other heavy weapons in the air during protests, injuring a small boy, according to an intelligence official who spoke on condition of anonymity because he wasn't authorised to release the information. In the southern city of Assiut, deputy police chief Yosri el-Jammasi said Salafist protesters beat up a group of protesters from the Communist party trying to join their demonstration. At one point, some in the crowd yelled back at a speaker who criticised the idea of constitutional guidelines.