LIMA — Protesters blocked key roads and forced the closure of five airports in Peru amid violent protests that flared up again on Friday and have left at least 16 dead, following the ousting and arrest of former President Pedro Castillo. Eight people were killed on Thursday in clashes between security forces and protesters in Ayacucho, according to local authorities, after a Supreme Court panel ordered an 18-month pretrial detention for Castillo while he is investigated over charges of “rebellion and conspiracy.” Demonstrators are calling for early elections, the closure of Congress, a constituent assembly, and the resignation of new...