Timeline of the Yemeni Revolution (January – 2 June 2011) Al Jazeera said Yemen had increased security the next day. Human Rights Watch said that demonstrators celebrating the ouster of Hosni Mubarak in Egypt turned violent when hundreds of men armed with knives, sticks, and assault rifles attacked the protesters. By noon, at least 4,000 protesters gathered to demonstrate in Sana'a, with numbers expected to rise. Approximately 5,000 police with clubs and government supporters beat the anti-government protesters who were celebrating the resignation of Egyptian President Hosni Mubarak and were also demanding the removal of Saleh. Protesters also tried to reach the Egyptian embassy in Sana'a, but police forces kept
Muslim Brotherhood in Egypt more radical Qutb-inspired Islamist groups blossomed, and after Sadat signed a peace agreement with Israel in 1979, the Muslim Brotherhood became confirmed enemies of Sadat. Sadat was assassinated by a violent Islamist group Tanzim al-Jihad on 6 October 1981, shortly after he had Brotherhood leaders (and many other opposition leaders) arrested. Again with a new president, (Hosni Mubarak), Brotherhood leaders (Supreme Guide Umar al-Tilmisani and others) were released from prison. Mubarak cracked down hard against radical Islamists but offered an "olive branch" to the more moderate Brethren. The brethren reciprocated, going so far as to endorse Mubarak's candidacy for president