The London-based NGO said Wednesday that the planes bombarded the IS positions in eastern and southern Kobani, which is located on the border with Turkey and inhabited mostly by Kurds.
The IS fighters, who attacked the town from the east and from the south, were targeted Tuesday by the coalition aircraft.
Meanwhile, clashes between the radicals and Kurdish irregulars continued in and around Kobani where the IS began its offensive Sep 16, forcing thousands of townspeople to flee across the border to Turkey and to other regions in Syria.
Earlier this week, Turkish authorities detained some 100 Kurds who had taken shelter in a school in the Turkish village of Ali Kur.
The refugees protested the decision to relocate them to Sanliurfa military prison.
Sanliurfa is a Turkish city close to the Syrian town of Tel Abiad that is controlled by the jihadis.