Reporting from VALLETTA, Malta — Three teenage migrants have been charged in Malta with seizing control of a merchant ship and using force and intimidation, a crime considered a terrorist activity under Maltese law. One of the accused was identified by the court during the arraignment Saturday as Abdalla Bari, a 19-year-old from Guinea. The other two are 15 and 16, and as minors could not be named. One is also from Guinea and the other from Ivory Coast. They are suspects in the hijacking in the Mediterranean this week of the El Hiblu 1, an oil tanker. The captain has said that migrants whom his crew had rescued began rioting and took control of his ship when they saw it was returning to Libya, forcing it to turn north toward Europe.