Four police officers have been killed after shots were fired during an anti-violence protest in Dallas, Texas, on Thursday evening.Officials said 11 officers in total had been shot. Some are Dallas police department officers and some Dart transit officers.A man holding a long rifle in a photo circulated by the police department has turned himself in, authorities said. It is not clear if he is a suspect in the attack. Another man, whom police have described as a suspect, is in custody after a shoot-out with officers.
Authorities said a suspicious package has also been found. The situation remains active.