Thirteen pilgrims were injured when a roadside bomb went off beside their bus in north Baghdad Sunday. Four days earlier, three Iranian pilgrims were killed and seven others injured by another bomb set off beside a pilgrim bus, this time in Samara. Attacks on Iranian pilgrims have been quite common over the years, but declined last spring. It isn’t clear if the two bombs in five days was a coincidence or the start of another raft of attacks on Iranian pilgrims.