The scheme has been criticised by Palestinian human rights groups, who point out that Hamas has previously banned sport from the school curriculum on the grounds that there is not enough time for it.
Hamas authorities introduced the 'Futuwwa', or youth programme into the state curriculum last September for 37,000 Palestinian boys aged between 15 and 17, conceiving it as a scheme intended to initiate a new generation of Palestinian men in the struggle against Israel.
Izzadine Mohamed, 17, was among the students who attended the weekly school classes, which covered first aid, basic fire fighting skills and how to fire a Kalashnikov rifle. He was also one of 5,000 boys across Gaza who also signed up for an optional two-week camp held at a Hamas military base.
"I was excited to learn the right way to use a weapon," said Mr Mohamed. "It's important because of the occupation. I feel stronger and more confident with the knowledge, which I could use against the occupier."
At the two-week camp, the boys spent their time dressed in a military-style uniform of black t-shirts and black jeans, and were trained by officers with the Hamas National Guard and militants with Hamas' armed wing, the al-Qassam Brigades.
Mr Mohamed said that as well karate and other street-fighting techniques, they were taught how to throw hand grenades, and how also how to protect themselves if one exploded nearby – "drop flat on the ground next to the grenade, it explodes outwards".
Hamas has denied that live weaponry is used in the course or that militants are involved in the training.
But Samar Zakout, of the Gaza-based human rights organisation Al Mezan, described it as "unbelievable" and likely to encourage Israel to see schools as targets during conflicts.
"They are trying to create a resistance culture, make our boys stronger to face Israel, but they shouldn't be doing it in schools. Maybe Israel will use this as a reason to bomb Gaza's schools in future," Mr Sakout said.
Mohamed Syam heads the education ministry in charge of the Futuwwa programme, which may be extended to girls' schools next year.
"We are not conducting military training in our schools, we are providing information," he said. "The youth can join military wings of factions, they don't need military training at school."
Yet an article written in Arabic on the Hamas ministry of education website credits the al-Qassam Brigades for its contribution to the course and notes their attendance at a graduation ceremony, also attended by Mr Syam. A YouTube clip showing a military demonstration in a Gaza school also appears to contradict the Hamas official line.
Posted on April 5, the video shows a mock Israeli military post erected in a school playground, where Palestinian militants enact a mock battle during which a faux Israeli soldier is killed and another captured. A shoulder-held rocket launcher is then fired at the military post, the force of the blast leaving only a smoking metal frame and a billowing Israeli flag.
Mr Syam said the video, which he claimed not to have seen, was not representative of the new initiative, and that the training course was designed mainly to school Gaza's youth in discipline and respect. "The military aspect takes up only one per cent of the course," he said.
"On the other side, in the occupied territory, [Israelis] are teaching the youth to hate and to kill Arabs and are training their teenagers in the military."
Israeli teenagers are drafted into an obligatory three-year military service after graduating from secondary school. There is no official Palestinian army. A number of armed militant groups, listed as terrorist organisations in Israel and Britain, operate in the Gaza Strip and are responsible for firing rockets into Israel.
