Iraq launched air strikes on Islamic State targets inside neighbouring Syria on Tuesday, destroying two buildings housing 40 fighters and weapons, its military said.

F-16 fighter jets destroyed a building where members of the ultra-hardline Sunni militant group were storing weapons, killing 10 of them. A second strike destroyed a building housing 30 Islamic State fighters, it said in a statement.

Islamic State, which once occupied a third of Iraq's territory, has been largely defeated in the country but has continued to carry out ambushes, assassinations and bombings there and still poses a threat along its border with Syria.

"The successful operation led to the destruction of a weapons warehouse ... that contained ten terrorists, rockets, and explosives belonging to Daesh (IS) gangs," the statement said.

The Iraqi air force has carried out several strikes against Islamic State in Syria since last year, with the approval of the Syrian government of President Bashar al-Assad and the U.S.-led coalition fighting Islamic State.

Iraq, which declared final victory over Islamic State in December, has good relations with Iran and Russia, Assad's main backers in the Syrian civil war, while also enjoying strong support from the U.S.-led coalition.

Islamic State has resorted to guerrilla tactics since it abandoned its goal of holding territory and creating a self-declared caliphate straddling Iraq and Syria.

(Reporting by Ahmed Aboulenein in Cairo; Editing by Kevin Liffey) ((ahmed.aboulenein@tr.com; +964 790 191 7021; Reuters Messaging: ahmed.aboulenein.thomsonreuters.com@reuters.net))