Iran’s capital Tehran has seen an unprecedented security tightening amid concerns that a country that has taken an active role in the fight against Isis could become a target for the terrorist group. Police have flooded the city in recent days, with armed officers wearing bulletproof vests stationed on main streets and standing guard outside major underground stations. Hossein Sajedinia, Tehran’s police commander, acknowledged this weekend that police numbers had been beefed up to ward off “any possible threat” and to make the citizens “feel secure”. “These anti-terrorist measures will continue as long as needed,” he said, adding this did not mean an attack was imminent. “Tehran enjoys complete security,” Mr Sajedinia added. Mainly Shia Iran has been free of much of the violence that has struck the region, particularly in neighbouring Iraq and in Syria, Tehran’s biggest Arab ally.