The airdrops Sunday were the first of their kind and followed weeks of U.S. and coalition airstrikes in and near Kobani, near the Turkish border.

The U.S. said earlier Sunday that it had launched 11 airstrikes overnight in the Kobani area.The airdrops came after ISIS fighters reportedly took heavy losses on Sunday.

Kobane's Kurdish defenders have been under IS assault for more than a month.They have weathered fierce street fighting and at least 2 terrorists suicide bombings but the front line remained unchanged on Sunday, a Kurdish official said.

"IS brought in reinforcements... and attacked hard," Idris Nassen told AFP by telephone. "But thanks to the Kurdish fighters' response, they did not make any progress."

From Saturday into Sunday morning, 31 terrorists died in the battle, said the Syrian Observatory for Human Rights.The Observatory said 15 terrorists were killed in the air strikes while 16 others died in ground clashes along with seven Kurdish fighters.

With the fighting raging, the corpses of at least 70 terrorists were brought over the past four days into an IS-controlled mortuary in the town of Tal Abyad further east, said the Observatory.

In a statement Sunday night, U.S. Central Command said U.S. C-130 cargo planes made multiple drops of arms and supplies provided by Kurdish authorities in Iraq. It said they were intended to enable continued resistance to ISIS efforts to take full control of Kobani.

The airdrops are almost certain to anger the Turkish government, which has said it would oppose any U.S. arms transfers to the Kurdish fighters in Syria.

Turkey views the main Kurdish group in Syria as an extension of the Turkish Kurd group known as the PKK, which has waged a 30-year insurgency in Turkey and is designated a terror group by the U.S. and by NATO.

President Barack Obama called Turkish President Recep Tayyip Erdogan on Saturday to discuss the situation in Syria and notify him of the plan to make airdrops Sunday, one administration official told reporters.

He would not describe Erdogan's reaction but said U.S. officials are clear about Turkey's opposition to any moves that help Kurdish forces that Turkey views as an enemy.

In a written statement, Central Command said its forces have conducted more than 135 airstrikes against ISIS forces in Kobani.

Central Command said, "Combined with continued resistance to ISIL on the ground, indications are that these strikes have slowed ISIL advances into the city, killed hundreds of their fighters and destroyed or damaged scores of pieces of ISIL combat equipment and fighting positions."

In a conference call with reporters after Central Command announced the airdrops, senior administration officials said three C-130 planes dropped 27 bundles of small arms, ammunition and medical supplies.

One US administration official declare on Sundaya land route to resupply the Kurds had been under discussion but would require Turkish cooperation. He said talks on resupply needs and means would continue.