US-backed Syrian fighters on Monday paused their offensive for a key dam held by ISIL to allow a technical team to enter the complex, a spokeswoman said.
There have been fears about the integrity of the dam after fighting in the area forced it out of service on Sunday, following earlier UN warnings that a collapse would be "catastrophic".
With air support from the US-led coalition against Islamic State of Iraq and the Levant (ISIL), the Syrian Democratic Forces (SDF) are fighting to seize the town of Tabqa and the adjacent dam on the Euphrates River, as part of their battle to take the hardline group's self-declared capital of Raqqa.