Bombs targeting the entrance of a landmark Ottoman railway building in Damascus and a feared security agency in Syria’s southeast killed at least 16 people Wednesday, activists reported.

There was no immediate assertion of responsibility for the attacks, but rebels tied to al-Qaeda have previously claimed bombings of security institutions and have also targeted the center of the capital, trying to take the war to the heart of President Bashar al-Assad’s power.

Eight people died and at least 50 were wounded in the blast at the country’s railways authority, housed in a century-old structure that was once the main Damascus train station, according to the state-run Syrian Arab News Agency and activists.

State TV broadcast images showing several wounded people walking from the blast site past apartment buildings and shops with their windows blown out. Part of the railway building’s wooden roof was shattered.

Also Wednesday, a suicide car bomb smashed into the entrance of the air force intelligence agency in the southeastern city of Sweida, killing eight people, activists said. State media reported a blast but did not say that it hit the security compound.

The Britain-based Syrian Observatory for Human Rights reported that a high-ranking officer was killed and that the other dead worked for the security agency. Syria’s air force intelligence is notorious for running detention centers where detainees are allegedly abused and sometimes tortured.

The blast in Sweida was a rare attack targeting a city dominated by Druze, members of a small, secretive Muslim sect that has mostly stayed on the sidelines of the Syrian war.

Syria’s 23 million people belong to a startling patchwork of religious groups, and the nearly three-year conflict has taken on increasingly sectarian overtones in the past year. Syrian rebels are overwhelmingly Sunni, and some of the strongest fighting brigades are formed of al-Qaeda loyalists. Assad’s security services are dominated by Alawites, a Shiite sect to which the Syrian leader belongs.

Syria’s minority Christians and Shiites have been targeted in previous attacks because rebels perceive them as siding with Assad.

The structure housing the Syrian railways authority was built during the rule of Ottoman Sultan Abdul Hamid II, according to a plaque affixed to the building.

It was part of the Hijaz train line that once stretched from the Ottoman Empire’s capital, Istanbul, to the holy Muslim city of Medina in what is now Saudi Arabia.

— Associated Press