By Sabine Siebold (Reuters) -Several European Union foreign ministers on Monday called for sanctions against Iran over the transfer of Iranian drones to Russia, as the bloc agreed a separate set of asset freezes and travel bans over Tehran’s crackdown on protests. The sanctions and threat of more will pile pressure on Iran’s rulers who have struggled to contain demonstrations sparked by the death in police custody of Mahsa Amini, a 22-year-old woman who was detained for “inappropriate attire”. Ukraine has reported a spate of Russian attacks with Iranian-made Shahed-136 drones in recent weeks, …