The operation to take Islamic State's last enclave in eastern Syria looked close to an end on Wednesday, with no sign of clashes as U.S.-backed fighters said they were combing the area for hidden jihadis.

Reuters reporters overlooking Baghouz from a hill on the bank of the Euphrates at the Iraqi border said the area was calm, and the Syrian Democratic Forces (SDF) militia searched for tunnels and landmines, an SDF official said.

The SDF on Tuesday captured an encampment where the jihadis had been mounting a last defense of the tiny enclave, pushing die-hard fighters onto a sliver of land at the Euphrates riverside.