(Updates with funeral, adds details, previous BEIRUT)
By Khaled Yacoub Oweis
DAMASCUS, Aug 3 (Reuters) - Syrian officials attended the funeral on Sunday of a senior security officer whose killing has shaken the tightly controlled country.
Brigadier General Mohammad Suleiman, 49, was killed on Saturday at a beach resort near the port city of Tartous, residents said. It was the first known assassination in Syria since the killing of Hezbollah commander Imad Moughniyah in Damascus in February.
Syria has been ruled by the Baath party since it took power in a coup in 1963 and banned all opposition. The security apparatus is key to Syria's support of the Lebanese Shi'ite movement Hezbollah, which fought a war with Israel in 2006, and exercises enormous influence on government.
A Syrian opposition Web site said Suleiman, a confidant of President Bashar al-Assad, had been shot in the head in his seaside villa. Another site said the shots had been fired by a sniper from a boat. The resort was cordoned off for hours and local media did not report the killing.
Assad was visiting Iran on Saturday. His brother Maher al-Assad, head of the Republican Guards, and other senior officers were at Suleiman's funeral in the town of Dreikish, east of Tartous, sources said.
The presence of Maher al-Assad, one of the most powerful figures in Syria, indicated Suleiman's pivotal role in the Syrian hierarchy and the high regard he enjoyed among members of the ruling class.
"This is earth-shattering. Since when do we hear of assassinations taking place like this in Syria? Suleiman was privy to many things," one of the sources told Reuters.
Arab media, including Lebanon's Future television station, had earlier reported the killing. There was no comment from the Syrian authorities, who pride themselves on maintaining stability in the country of 19 million people.
Their reputation for control has been challenged in the last two years by a series of violent events.
Scores were killed and injured last month in violence at a prison run by the military, and a car bomb killed Hezbollah commander Imad Moughniyah in a district of Damascus swarming with security on Feb. 14.
The Damascus government, which is engaged in indirect peace talks with Israel, had hinted that the Jewish state was behind the attack and said it would swiftly present "irrefutable" proof of who was behind the assassination.
But no results of an official investigation the authorities said they were conducting were revealed.
The talks with Israel started several months after Israeli planes raided a military target in eastern Syria last year. The United States, Israel's chief ally, said the site was a nuclear complex under construction. Syria denied it was building an illegal nuclear facility. (Additional reporting by Nadim Ladki in Beirut; Editing by Janet Lawrence)