At least one child has been shot dead and another arrested as Syrian pupils protested against the government on the first day of the new school year.

Eleven-year-old Ibrahim Mohammed al-Farouj from Sanamein was killed by a bullet to the head, activists said, exactly six months after a group of schoolchildren in the southern city of Deraa sparked the first protests of the uprising against president Bashar al-Assad.

Some schools remained closed because they had been used as holding centres for detained protesters or because teachers had been arrested, according to sources across the country. In other areas, troops used live ammunition to disperse students who had boycotted classes, chanting "No studying, no teaching until the president is toppled."

Sameh al-Hamwi, an activist in Hama, said: "The government postponed the opening of many schools to Tuesday." He estimated that more than half the parents in the city were planning to keep their children at home amid fears for their safety.

In the flashpoint city of Homs, locals said at least one child was arrested from a school in the wealthy Ghouta area. Amateur footage posted online showed children in another school in the city trampling on posters of Assad. At a third school, children tore up their citizenship textbooks.

A former student of Ghasaniee, a school in Homs which had been used as a temporary detention facility, did not re-open, according a former student, who said a friend of his had found the playground full of discarded bullet casings and walls pockmarked with holes.

For the past six months, young people have been on the frontline of anti-government protests which broke out after a dozen children – all aged under 15 – were arrested in Deraa for scrawling anti-regime graffiti on a wall.

But children have also been victims of the regime's violent response: 182 Syrians under the age of 18 have been killed and scores more tortured, according to Radwan Ziadeh, a US-based human rights activist from Syria and head of the Damascus Centre for Human Rights.

In one notorious case, the mutilated body of Hamza al-Khateeb, 13, was returned to his parents in May after he had been arrested by security forces. His neck had been broken and his penis cut off.

"Children have been living the deaths and arrests of their family members and even friends," said Razan Zeitouneh, a human rights lawyer in Damascus. "It has stolen their innocence and childhood."

Nour Ali is the pseudonym for a journalist based in Damascus