A mortar shell hit the French school in the Syrian capital Damascus on Sunday without causing any injuries to children in class at the time, officials said. "A mortar shell landed on the chimney of a classroom around 9:00 am (0700 GMT). No one was hurt but the windows shattered and the walls cracked," school receptionist Bashir Oneiz told AFP. Aline Farah, a nurse at the Charles de Gaulle school in the upscale central district of Mazzeh, said students were in class when the mortar struck. "It was a miracle that no one was hurt, neither students nor teachers nor employees," she said. "They were all crying. They were terrified. We took them to an underground shelter," said Farah, adding that the sound of the explosion had been "very strong". "When the blast hit, the parents came to pick up their children," she added. Only the school's staff remained behind after the parents left with their children, said an AFP photographer at the scene. The only foreign school still open in the Syrian capital, the Charles de Gaulle currently has about 220 students, down from a pre-war population of 900. It caters both to Syrian students and the children of a few remaining foreigners living in the country despite a brutal 32-month conflict between the government and rebels. Rebels in rear bases on the outskirts of Damascus have regularly fired rockets and mortar rounds into the centre of the capital. But in recent weeks, the attacks have become more frequent and increasingly deadly.