A top UN official in Central African Republic says the latest upsurge in deadly violence saw the first use of heavy weapons and more sophisticated military tactics by a predominantly Christian armed group. <br/><br/>UN deputy special representative Diane Corner said in a video news conference yesterday that more than 150 people, including six UN peacekeepers, have been killed and over 20,000 have been displaced since May 8 in southeastern Bangassou, southern Alindao and northern Bria. <br/><br/>Corner says the fighting is "more complex" than a renewal of sectarian violence between Christians and Muslims that has plagued the country since late 2013.