Iraqi forces launched an attack to drive Islamic State from the last territory it holds in Iraq on Thursday and the Syrian army and its allies said they planned to march on the jihadist's last Syrian stronghold.
The separate assaults across the Iraqi-Syrian frontier aim to deal a final blow to the Islamic State "caliphate" that has crumbled this year in Syria and Iraq, with the group losing the cities of Mosul, Raqqa and swathes of other territory.
Iraqi Prime Minister Haider al-Abadi said Islamic State fighters would have "to choose between death and surrender" as he announced the offensive on the region of Rawa and al-Qaim, which is located at the Syrian border.
The Iraqi air force dropped thousands of leaflets on the border area calling on militants to surrender and urging the population to stay away from their positions, according to a statement from the Joint Operations Command in Baghdad.