CAIRO - Two men were killed in a bomb blast in Cairo on Thursday, security sources said, one of several explosions on the anniversary of the army’s removal of Egypt’s elected Islamist president Mohamed Morsi.Security was tight in Cairo as armoured personnel carriers blocked off the city’s central Tahrir Square, one year after former army chief Abdel Fattah al-Sisi, now Egypt’s new president, deposed Morsi of the Muslim Brotherhood.The explosion occurred in a flat in Kerdasa, a western district of the capital, where around 10 policemen were killed in an Islamist mob attack last summer, the security sources said.Another explosive device detonated on Thursday in a car near the Abbasiya presidential palace in northeastern Cairo and three home-made bombs went off near police cars in the central district of Imbaba without causing injuries, the sources added. There were no immediate claims of responsibility.Cairo has been hit by a spate of small blasts in recent days. Two police officers were killed on Monday trying to defuse bombs planted near the presidential palace.Last week, a series of makeshift bombs exploded at Cairo metro stations, the first in the capital since Sisi was sworn in as president.In the period following Morsi’s overthrow last July amid mass protests against his rule, security services unleashed a crackdown on Muslim Brotherhood politicians, activists and street protesters, jailing thousands and killing hundreds in clashes and raids.Since then, some radical Islamist groups have repeatedly targeted police and soldiers in the capital and elsewhere, mostly by planting makeshift bombs.The Muslim Brotherhood, which Egypt has declared a terrorist organisation, denies any link to the violence.However, opponents of Morsi’s ouster have called for mass protests following afternoon prayers on Thursday.“On July 3, Egyptians will revolt, marking the beginning of the end of the coup, marching from all towns and cities across Egypt to liberty squares in all provinces,” the anti-coup alliance said in a statement released late on Wednesday.A Reuters witness said clashes had already broken out in the upscale Cairo district of Mohandiseen on Thursday. The Muslim Brotherhood’s political arm, the Freedom and Justice Party, said on its Facebook page that protests had also begun in the impoverished Cairo districts of Haram and Materiya.The authorities’ security dragnet has expanded over the past year to include secular and liberal activists, including many who played leading roles in a 2011 popular revolt that ousted veteran leader Hosni Mubarak after 30 years in power.A law passed after Morsi’s fall has sharply restricted the right to protest. Last month, around 23 activists were arrested over a rally in Cairo against the new law.Western governments and rights groups have voiced concern for freedom of expression in Egypt and the security clampdown has dimmed hopes for democratic evolution in Egypt that had soared after the anti-Mubarak uprising three years ago.The jailing last month of three Al Jazeera journalists for seven years on charges of assisting banned Islamists caused an international outcry, which Cairo rejected as interference.Amnesty International condemned Egypt’s human rights record in a statement on Thursday, saying torture, arbitrary arrests and detentions had increased since Morsi’s political demise.“Egypt’s notorious state security forces - currently known as National Security - are back and operating at full capacity, employing the same methods of torture and other ill-treatment used during the darkest hours of the Mubarak era,” said Hassiba Hadj Sahraoui, deputy director of Amnesty’s Middle East and North Africa programme.Sisi’s administration says it is committed to a democratic transition and the rule of law following the 2011 uprising.