The attack on the post separating the Syrian town of Kobane from Turkey was followed by fierce clashes between Kurdish and IS fighters.
"Clashes broke out for the first time in the area after two jihadist attacks at dawn on the border post separating Turkey and Kobane," said Rami Abdel Rahman, head of the Syrian Observatory for Human Rights monitoring group.
One suicide attacker blew up an explosive-packed car, and another detonated a suicide-bomb belt, according to the Britain-based Observatory.
There were conflicting reports about whether the attackers came from the Syrian or Turkish side of the border.
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A Turkish official confirmed that two explosions were heard "on the Syrian side of the border."
"The Islamic State mounted attacks near the border gate. There were violent attacks at around 5:00 am (0300 GMT) this morning," the official told AFP.
The Observatory said the attackers had come from the Turkish side, something Turkish officials denied.
IS began its assault on Kobane more than two months ago, but Kurdish fighters backed by US-led air strikes and Iraqi Kurdish peshmerga forces, have prevented a full takeover of the town.