CAIRO - Egypt's presidency and prime minister said on Saturday security forces in North Sinai were working to return Coptic Christians living near Egypt's border with Israel to their homes after they fled in fear of attack from Islamists.Nine Christian families living in Rafah near Egypt's border with Israel left their homes on Friday after Islamist militants made death threats and gunmen attacked a Coptic-owned shop.Analysts say Islamists with possible al-Qaida links have gained a foothold in Sinai and the departure of the families could fuel concerns about religious tolerance and the rise of militancy after the overthrow of President Hosni Mubarak."The Coptic families quit their homes pre-emptively but the governor of North Sinai has given orders to return them to their homes and this is being carried out now," said Yasser Ali, presidential spokesman.Two armed men riding a motorcycle opened fire on a Coptic-owned shop in Rafah on Wednesday but no one was injured.Prime Minister Hisham Qandil said militants had not tried to force the Coptic families from the border town and they had left of their own accord. However, death threats against the Copts had been printed on flyers circulating in the desert area."We must uproot fear and provide all security measures to every citizen," Qandil said.Israel has voiced concern about security in Sinai, where at least four cross-border attacks have taken place since Mubarak was toppled in February 2011.Egypt's new president, Mohamed Mursi, has vowed to restore order. But efforts to impose central authority are complicated by the indigenous Bedouin population's ingrained hostility to the government in Cairo.