MOSCOW (Reuters) - A Russian general killed in Syria had been seconded to the Syrian government as a military commander, Russia s military chief of staff said on Wednesday. Moscow has long been a staunch ally of Syria, but the role of the deceased general reveals the extent to which Russia has become an integral part of President Bashar al Assad s ruling system. Lieutenant-General Valery Asapov, 51, was killed on Saturday by shelling from Islamic State positions near Deir al-Zor. He was the chief of staff of Russian forces deployed to the country and later became the commander of Syria s Fifth Corps of volunteers, chief of general staff Valery Gerasimov said. It was known that the Syrian Fifth Attack Troop Corps of volunteers, formed in late 2016, was equipped and advised by the Russians, but Damascus and Moscow had not previously announced it was under Russian command. Speaking at Asapov s funeral, Gerasimov said:  High prestige combined with care were outstanding features of his work.  Of course, those qualities were displayed during his working trip to the Syrian Arab Republic, where he had been deployed from February this year,  Gerasimov said, addressing Asapov s family and colleagues.  He worked as the chief of staff of the group of our forces and then was in command of the Fifth Corps of volunteers ... A treacherous shell cut short his life.  A security specialist, who worked in Syria alongside the Russian and Syrian military, said Asapov was de facto the commander of Syria s Fifth Corps but he may have been listed as chief military adviser on paper.  Syrian officers relied completely on our officers,  he said. Hundreds of people, most of them from the Russian military, attended the funeral at the Federal Military Memorial Cemetery for Asapov who became the highest ranking military officer to be killed in the Syrian war. Inscriptions in Russian and Arabic on some of garlands said they were sent by President al-Assad, Syrian ministers and military commanders. 