The New Year's Day bombing of a church suggests Al-Qaeda-inspired militants have a toe-hold in Egypt, but probably does not indicate a return to the kind of insurgency that Egyptian forces crushed in the 1990s. No clear official account has emerged of how the Jan. 1 attack, which killed 21 people, was carried out, but analysts point to a small cell, not a bigger militant group like those which challenged the government more than a decade ago. Whoever was behind it, the attack seemed designed to upset Egypt's fragile sectarian balance. It was the biggest attack in at least a decade aimed at Coptic Orthodox Christians, who form 10 percent of Egypt's 79 million people. The reaction was swift. Within moments of the blast, Christians took to Alexandria's streets in protest. Some Muslims and Christians hurled stones at each other. A day later police fired teargas in Cairo to disperse angry crowds. “I do not expect a spread of terrorism in Egypt and a return of terror attacks that took place in the 1980s and 1990s,” said Amr Elchoubaki, an expert in militant movements at the Al-Ahram Center for Political and Strategic Studies. “But I am more concerned about the internal climate and the impact of any attack, even if limited, on relationships between Muslims and Christians,” he said. The government was quick to call for national unity, blamed foreign hands and pledged to track down the perpetrators. Whether it involved Egyptians or foreigners, analysts said the scale, planning and timing suggested Al-Qaeda-inspired militants may have been behind it. It followed calls, made on the Web, for attacks on Coptic churches at this time. “The first and most likely possibility is that a sleeper cell of an Al-Qaeda group carried out this operation and this would mean that Al-Qaeda has penetrated the Islamic political movement in Egypt,” said analyst Nabil Abdel-Fattah. The state crushed groups such as Al-Gama'a Al-Islamiya and Islamic Jihad, which targeted tourists, Christians, government ministers and other officials in a 1990s campaign for a purist Muslim state, and has kept a tight lid on such groups since.