A deputy commander in a Syrian Turkmen brigade claimed that his personnel shot and killed the crew while they were descending in their parachutes, while some Turkish officials subsequently stated that the crew was still alive. The weapon systems officer was rescued by Russian forces but the pilot was killed by rebels, along with a Russian marine involved in a helicopter rescue attempt. Russian president Vladimir Putin warned Turkey of serious consequences. In an effort to increase safety during aerial operations in the region, Russian fighter jets would escort bomber missions, S-400 SAM systems were deployed in Syria and a Russian cruiser was stationed off the coast of Syria to protect Russian aircraft. Following the incident, Russia announced that Su-24s in Syria had been armed with air-to-air missiles on operational sorties.