"The attack was launched from the desert on the Iraqi side of the border," said a senior military officer with an army division stationed in Rutba, the nearest town.
The Al-Walid crossing, which lies 515 kilometres west of Baghdad, was attacked shortly after midnight.
"The attack was repelled by the tribal forces manning the crossing, with the aerial support of the international coalition," the officer told AFP.
The officer and a local official from Anbar - the vast western province which has borders with Syria, Jordan and Saudi Arabia -- said the tribal fighters neutralised the two vehicles before they could reach the border position.
It is comprised of around 100 men from Anbar clans and their commander is Shaker al-Rishawi.
Iraqi forces have over the past 18 months retaken most of the major towns and cities in Anbar but IS retains some fixed positions near the Syria border and some desert hideouts that allow it to continue harassing government troops across the province.