. >> the president of nigeria, muhammadu buhari is hosting a summit in the coming hours. the u.s. department of state and other leaders are attending this event. the latest global terrorism index named boca haram the deadliest terrorist group in the world. they are responsible for killing an estimated 20,000 people since 2009. the group pledged its allegiance to isis just last year. >> what we've seen are reports of more cooperation between them. what we've seen is boca haram itself being more sophisticated in its messaging or propaganda, if you prefer. and that bearings the hallmarks of da'esh which is unfortunately very sophisticated at doing that. and also reports of boca haram fighters in libya, with da'esh fighters. so these are all elements that suggest that there is -- that there are more contacts. and more cooperation. and is this, again, something that we're looking at very, very carefully because we want to cut it off and we want to prevent it from going any further. >> following it all, our david mckenzie is live in johannesburg this hour. david good to have yo