MOSCOW (Reuters) - Russian Prime Minister Dmitry Medvedev complained on Friday that U.S. cruise missile strikes on a Syrian airbase were one step away from clashing with the Russian military.

U.S. officials informed Russian forces ahead of the strikes -- intended to punish the Syrian government for what they say was a chemical weapons attack earlier this week -- and avoided hitting Russian personnel.

Satellite imagery suggests the Shayrat air base that was struck is home to Russian special forces and military helicopters, part of the Kremlin's effort to help the Syrian government fight Islamic State and other militant groups.

Medvedev, writing on social media, said the U.S. strikes were illegal and had been "one step away from military clashes with Russia."

(Reporting by Denis Pinchuk; Editing by Andrew Osborn)