In the ornate grounds of Mellat Park in Tehran, a teenage boy, buried in his phone, suddenly stops in front of a man sitting on a bench with his wife and young daughter -- both covered from head to toe in the conservative black chador robes.
The family stop their conversation and stare at the boy, who appears to be pointing his phone at them. Then, the boy moves on, completely oblivious -- his mind is in the virtual world of Pokemon.
Iran blocks many global news and social media sites, including Facebook and Twitter.
It banned Pokemon Go just a few days after it was released in early July, citing national security concerns because the wildly popular game leads users to real-life locations via GPS maps on their mobile phones.
"Because this game is a mixture of virtual and physical games, it can pose lots of problems for the country and people in terms of security," deputy attorney general Abdulsamad Khoram Abadi told the Tasnim news agency on Friday.
He confirmed Pokemon Go had been unanimously banned by the High Council for Cyberspace.
"These games can become a means for directing guided missiles and even cause disruptions to ambulances and fire trucks," Alireza al-Davoud, a hardliner-linked analyst told Tasnim, adding he feared the US developers of the game were using it to spy on Iran.
BYPASSING THE CENSORS
But the ban has done little to stop determined gamers hunting down Pokemon creatures.
Iran's youthful and highly connected population is used to bypassing internet censorship on a daily basis, using "VPNs" that mask the location of their phones and computers.
Most phone shops sell pay-as-you-go VPN cards featuring the logos of banned sites such as Facebook and YouTube.
The authorities rarely crack down on this behaviour, preferring to discourage access to foreign sites, rather than rigidly enforce censorship.
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The bigger problem for Pokemon Go fans in Iran is the lack of "Pokestops" and "Gyms" to discover.
Mellat Park is a relative hotspot, with one Pokestop and two Gyms. On a recent evening, it had attracted around 30 gamers, mostly in their teens and 20s.
"It just shows how little data there is about Iran on the internet," says 15-year-old Shayan, complaining about the lack of features in Tehran.
Pokemon Go automatically assigns creatures and play areas based on existing map data, which is fairly limited in the Iranian capital.
Some people have travelled from the town of Karaj, 30 kilometres (18 miles) west of Tehran, to play here, adds Shayan.
The city's notorious traffic is another annoyance.
"Last night, there were seven of us stuck in traffic for an hour trying to go and capture three Gyms," says Hossein, 26, laughing.
Although gatherings of young men and women are frowned upon by Iran's conservative authorities, the meet-up in Mellat Park draws little attention since everyone is glued to their phones.
One family does figure out what is happening and stops to ask the youths how it works.
"Look how cool it is," says Shireen, who is with her husband and four-year-old son.
"I really like it because you have to move. I will let my son play it, but only after he's 15," she laughs.
As everywhere, the game is popular because it drags gamers off their sofas and into the real world.
"After a day of work, I would have never come outside if it wasn't for this game," says Siavash, who says he lost four kilos (nine pounds) in the first two weeks after it came out.