ANGOLAN officials have banned the managing editor of an independent weekly, William Tonet, from leaving the country, after he was interrogated several times, sources at his paper said on Monday. Tonet, director of Folha Oito, was notified of the ban by emigration authorities on Saturday, after being questioned by criminal investigators about alleged defamation and spreading news endangering state security. Another independent journalist and correspondent for the Portuguese weekly Expresso, Gustavo Costa, has been banned from leaving the capital Luanda, sources said.