Iranian protesters clashed with police in a town near the capital on Thursday, reportedly killing or wounding a number of members of the security forces, who at one point dropped stun grenades on the demonstrators from helicopters.
It was the latest in a wave of demonstrations that have convulsed Iran for more than six weeks and mark one of the biggest challenges to the country's clerical rulers since they seized power in the 1979 Islamic Revolution.
The protesters had gathered in Karaj, just outside Tehran, to mark the 40th day since the shooting death of Hadis Najafi, 22, one of several young women to have been killed during the protests. The demonstrations were ignited by the death of another woman held by the country's morality police.
The 40th day after someone's death has great symbolism in Shiite Islam and is marked by public mourning. Commemorating protester deaths has given momentum to the ongoing demonstrations, just as it did during the 1979 revolution that overthrew a Western-backed monarchy.
Videos circulated online showed thousands of protesters in Karaj and clashes with police. In one of them, a helicopter flies over the protesters and drops flash grenades in an attempt to disperse them before landing in the middle of a highway. Government supporters on social media said the helicopter was sent to aid wounded policemen.
The state-run IRNA news agency tweeted that police were attacked in the area and posted a video showing a police pickup truck that had crashed into a concrete barrier on a highway.
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