The Syrian Observatory for Human Rights reported that a bomb blast in northern Syria targeted a military vehicle on Monday on the road from Ain Issa to a military base where some of the U.S.-led coalition against Islamic State are located.
The blast killed at least one person and injured others of unknown nationality, the Britain-based war monitor reported, in an area controlled by the coalition-backed Syrian Democratic Forces, an alliance of Kurdish and Arab militias.
Spokesmen for the U.S.-led coalition and the SDF were not immediately available for comment.
With air and special forces backing from the coalition, the SDF has captured almost all of the quarter of Syria east of the Euphrates since beginning a campaign against Islamic State in 2015.
The Observatory also reported on Monday that the SDF had made wide advances against Islamic State in one of the last desert areas it controls near the border with Iraq.
The jihadist group holds only a few remote pockets of ground in eastern Syria after the SDF offensive and a rival one by the Syrian army backed by Iran and Russia.