Police fired tear gas to disperse a crowd in Cairo on Friday as protesters marked the passing of 100 days since the storming of two sit-ins in the capital.The Rabaa al-Adawiya mosque was the scene of one of the protest camps in support of former president Mohamed Morsi, where thousands were killed when it was stormed by security forces on August 14.Protesters were reportedly attempting to make their way back to Rabaa al-Adawiya square, in a Cairo suburb.But security forces had cordoned off the area, firing tear gas to prevent the march from reaching the square, according to a Reuters witness.A 10-year-old boy shot dead on Friday near clashes between supporters and opponents of deposed Islamist president Mohamed Morsi in Egypt's northern city of Suez, security and medical sources said.Morsi's supporters have staged frequent protests across Egypt, many of them after Friday prayers, since the army deposed him on July 3 in response to mass protests against his rule, and arrested most of the top leaders of his Muslim Brotherhood.On Friday, around 500 supporters of Morsi gathered in the central Awel-el-soor neighborhood of Suez and chanted slogans against the army and police. Clashes broke out with opponents of Morsi and rocks were thrown and shots exchanged, witnesses said.The child, Samir El-Gamal, was hit by a bullet in the back of the head, the sources said, while walking with his mother near the clashes. His mother was unharmed, but the boy died on the spot, they said.Members of Morsi's Muslim Brotherhood accused the security forces of using live rounds to disperse their protest, residents of Suez said. Police said the bullets had come from the opponents of the protesters, not from security forces.The child's family accused the Brotherhood of responsibility for their child's death, the state news agency MENA said.The interim government installed in July has waged a broad crackdown on the Brotherhood, accusing its leaders of fomenting violence or terrorism, accusations they deny.The government has promised a return to democratic rule next year, under a new constitution. In the interim, the political turmoil that has gripped Egypt since the overthrow of Hosni Mubarak in early 2011 continues to undermine both stability and economic growth.Elsewhere, hundreds of pro-Brotherhood protesters tried to force their way into the embassy of the United Arab Emirates in Cairo and attacked its guards, but police used teargas to disperse them, the state newspaper al-Ahram said.Since Morsi was deposed, the UAE and other Gulf Arab allies have shown strong support to the interim government, pledging billions of dollars to help shore up Egypt's fragile finances.In the Nozha area of central Cairo, pro-Morsi protesters threw petrol bombs at two carriages of a tram, but police put out the fire, security sources and MENA said.