The pitch is bone-hard, the goalposts are improvised and the kit is mostly borrowed. Referees are in short supply and no one really knows the Arabic for "prop forward". And for decades the sport was banned by the Gaddafi regime – which considered it too violent.

But rugby is enjoying something of a surge in popularity in Libya, and may be its fastest-growing sport. From a standing start after the revolution, there are now eight teams in a national league and a dozen more forming, with the local federation chasing membership of the International Rugby Board.

"Rugby is a bridge; it doesn't know politics," said Tarek Benrewin, 28-year-old administrator of the Libya Rugby Technical Committee, standing on the touchline of a freezing pitch as three clubs competed in a national seven-a-side tournament. "We have teams forming across the country."

The tournament – held in Benghazi and Tripoli – is not short on full-blooded aggression, even if the goalposts have had to be fashioned with white poles strapped to football goalposts. But enthusiasm is undimmed. "Libyans like this game, it suits us," said Wael Aradi, 25, who captained a national side in its only foreign outing, to Egypt.

Among a sprinkling of foreign players is Francis Ward, 27, an aid worker who plays fly-half at Hampstead Rugby Club. "It's progressing really fast, there's a lot of talent here," he says. "The big difference is the depth of strength in the sport that we have in the UK; you just don't have that here."

Rugby in the north African country has had a rocky history. For any sport to succeed in the Libya of Muammar Gaddafi, one of his sons needed to take an interest. None did. The dictator's eldest son, Muhammad Gaddafi, president of Libya's Olympic committee, did turn up at a game in 2001 – only to declare it a "violent sport". Like boxing in 1979, it was then banned by his father's idiosyncratic green book.

"That was why our sport was banned," said Karim Ferjani, the committee's general secretary. "All because of that stupid book."

Further trouble also came in 2001, when a match was played on a football pitch adjacent to the beach house of Saadi Gaddafi, a keen footballer. "He came out and was furious, blaming us for the state of the field," said Benrewin. "He demanded to know who was in charge. A British player said he was, because if a Libyan admitted to that, he would be in big trouble."

In 2006, Benrewin went to the sports ministry to arrange a pitch after the French embassy asked if the crew of a visiting warship could play the Tripoli Barbarians, who had been discreetly formed by British and French immigrants in 1998. He was arrested and interrogated for six hours about his proposed fraternisation with a foreign power. Later he was too nervous to contact the French to say the game was off. "I ignored the [French embassy] phone calls for three weeks, I still feel bad about it, but I didn't dare pick up."

Worse followed, when four players from a Tripoli Barbarian sevens team died in a bus crash en route to play in Benghazi in 2007. The team was dissolved as a mark of respect.

By then, however, political pressure had forced the game underground, with the remaining players arranging fixtures in secret at Regatta, a foreigners-only compound on the coast in Tripoli and away from the authority's prying eyes.

Even there, the Gaddafi curse followed, with another son, Mutassim, blaming the Regatta groundsman for a chewed-up pitch. He beat the man up in a drunken rage and threw him into the boot of a car, to be dumped on the road, mercifully still alive.

These days, the biggest problem is a lack of referees: Libya has just two, neither qualified. Even this reporter was approached before the first game, handed a red and yellow flag, and asked if he could run the line.

Regatta's referee is Muhammad Bakrami, 33, a computer programmer who learned the rules from British rugby websites. He journeys 50 miles from his home in Zawiya to officiate.

Today he is wondering why he bothers. "The players don't respect us," he said after a verbal assault from three, who found themselves banned for a month. "Bad words are OK, I suppose. As long as they don't shoot me, I don't mind."

Next up, the best Tripoli teams play the best from Benghazi, hoping that the tournament will help the growing rift between the east and west of the country. "We make friends with feasts after the games," said Benrewin. "We call those feasts the third half."