BOSTON—Taliban websites that delivered the extremist group’s official messages to Afghans and the world at large in five languages went offline abruptly Friday, indicating an effort to try to squelch them. It is not immediately clear, though, why the sites in the Pashto, Urdu, Arabic, English, and Dari languages went offline Friday. They had been shielded by Cloudflare, a San Francisco-based content delivery network and denial-of-service protection provider. Cloudflare has not responded to emails and phone calls seeking comment on the development, which was first reported by The Washington Post. The Cloudflare shield prevents the public from knowing who exactly hosts the sites. Also Friday, the popular encrypted messaging service WhatsApp removed a number of Taliban groups, according to Rita Katz, director of SITE Intelligence Group, which tracks online extremism. The websites’ disappearance may just be temporary as the Taliban secures new hosting arrangements. But the reported removal of the …