On any given Friday, groups of young women across Iran can be seen jumping from rooftops, scaling the graffitied walls of apartment blocks, and catapulting themselves over stairways. They are not being chased by riot police, but merely practising their parkour moves, especially the ground roll, tricky to execute while wearing a headscarf.

Parkour's popularity among young women in Iran is soaring, despite the bulkier clothing and head coverings Islamic dress codes require them to wear. The outdoor sport, a fast-paced hybrid of gymnastics and martial arts, seems designed to get you out of a fix quickly, which perhaps explains its appeal to young Iranians, whose social lives in the strict Islamic republic often require considerable agility. Iran's female practitioners are running their own threads on Persian-language forums and posting films online to showcase their skills. Unlike the men's scene, with its heavy rap culture overtones and emphasis on group rivalries, the girls' movement comes across as more athletic and purposeful, despite the greater challenges women face practising outdoors.

Men hold major parkour tournaments in urban parks and talk openly online about parkeur being accepted by local police. Not so for women, whose equal access to sports facilities and public areas for exercise has long been contested by the government.

The authorities may tolerate matrons doing aerobics in parks, but young women dashing over obstacles pushes the boundaries of acceptability. One young woman, hiding behind oversize sunglasses, says in a YouTube clip: "It's become quite acceptable for guys, but because we're girls, when we're out practising, they sometimes hassle us."

What's striking about parkour's appeal among Iranian women is the sheer breadth of the trend. It's not being led by the reed thin, Fendi-clad women of north Tehran, but girls in trainers and practical headscarves (maghnaeh) from Lahijan to Shiraz. Parkour's punchiness seems to resonate among Iranian women, who in recent years have also taken up martial arts in record numbers.

The context is the bullying culture and street violence that women face under the country's Islamic government, whose discriminatory laws make seeking legal recourse for domestic violence almost pointless.

Women in Iran, who make up 60% of graduates, have never had so much to feel angry about, with the state increasing gender segregation at university, among other changes.

Nooshin, a councillor for Iran's welfare organisation in the city of Hamedan, says she has seen women's awareness of their own physical capabilities shifting. "Do you think it's coincidence that more women are taking karate and kung-fu classes? Women, especially young women, are learning about their rights and fighting back." Even in the rebellious milieu of Iran's parkour scene, where you encounter endless clips set to edgy Persian hip-hop and would expect to find more progressive social mores among men, women's involvement has met with criticism. One young man questioned on the national parkour website whether the sport was in line with women's "modesty and chastity". But in film clips online there are also scenes of men standing by to aid women doing air somersaults, clearly enjoying their role as helpers.

As one student from a Tehran parkour clan says: "It gives us courage and helps us release our pent-up energy. It's great to feel that nothing can stand in your way."