After refugees, radicalism and border skirmishes, Jordan is now facing a new spillover from Syria’s civil war: assassinations.

Maher Khaled al-Rahal, a leader of the Free Syrian Army, was shot dead in an alley on Friday on the outskirts of Amman. Jordanian police have not yet identified the gunman, who shot Mr al-Rahal five times with a pistol.

While Jordan, a long-term ally of Britain and the West, has sought to help the rebel movement and is sheltering hundreds of thousands of Syrian refugees, King Abdullah fears that the civil war on its border will ignite sectarian conflict at home and incite terrorist attacks.

Mr al-Rahal, 27, was a field commander with the Liwa al-Mujahidin brigade just over the border in Syria’s Deraa province. He entered Jordan a week ago to visit family by arrangement with Jordanian intelligence, which maintains contact with FSA members.

Despite suggestions that his murder was an act of revenge by fellow Syrians from his deeply tribal village of Inkhel, family members and colleagues blamed the Syrian regime.

“Maher had no enemies in Deraa, but the regime always seeks to liquidate the leaders who work well on the ground,” said his brother-in-law.

“We know we are all targeted by Assad’s gangs, in any place and at any time,” said Abu Ayesh, a senior member of the same battalion as Mr al-Rahal. “This killing increases our resolve to respond to this criminal regime.”

Mr al-Rahal’s brigade belongs to the Hamza battalion, which is part of the Deraa military council, which connects rebel units in the field with the FSA’s supreme military council and foreign backers, including the US.