WASHINGTON: US officials say that after months of delays and vetting, the training of Syrian rebels has started in Jordan as part of a broader effort to build a force capable of fighting Islamic State extremists.

Jordan is the first of the four training sites to begin instruction. Others are in Saudi Arabia, Qatar and Turkey.

More than 3,750 Syrian fighters have volunteered for the training, and about 400 have completed the pre-screening.

There are about 450 coalition forces involved in the training at the four sites, including about 350 Americans.

The US has spent months vetting the fighters to try to make sure that any enemy combatants or extremists are weeded out. Officials spoke on condition of anonymity because they weren’t authorized to discuss it publicly.