A 19-year-old star wrestler and two other young men were hanged in Iran this week, raising alarm among rights groups that a wave of executions may be under way as authorities facing relentless attacks from the US and Israel seek to squelch public dissent. The three men are the first to be executed from among the tens of thousands who were arrested during a January crackdown on nationwide protests. Rights groups say more than 100 others could face death sentences. The wrestler, Saleh Mohammadi,...