Iranian protesters remained defiant Monday with students staging sit-ins and some industrial workers going on strike despite a crackdown activists say has left dozens dead and hundreds more imprisoned. Videos posted on social media indicated that protests flared at various points in the capital and other cities over recent days, with women burning headscarves and shouting slogans against the Islamic republic. Kurdish rights group Hengaw accused the authorities of using heavy weaponry, including “shelling” on neighbourhoods and “machine gun fire”, in the northwestern city of Sanandaj — claims …