CAIRO (Reuters) - Syrian Democratic Forces (SDF) have captured two Islamic State militants of American nationality, according to a statement dated earlier this month that was sent to media on Saturday.

In the statement dated Jan. 6, 2019, the U.S.-backed SDF alliance, led by the Kurdish YPG militia, said the pair were captured during operations against Islamic State in Deir al-Zor province along with two Pakistanis and an Irish citizen.

On Thursday, the SDF vowed to ramp up attacks on Islamic State remnants and cells, a day after a bomb attack killed four Americans in northern Syria.