SEVASTOPOL (AFP) - Pro-Russian militants smashed through the gates of a Ukrainian air force base in Crimea on Friday in the latest signs of boiling tensions on the rugged peninsula, Ukraine's defence ministry said.

The militants entered the base and were in negotiations with the commander of the base, while soldiers guarding it have locked themselves in their barracks, a ministry spokesperson told AFP.

No shots were fired in the incident.

Another Ukrainian military official said the incident began at 1740 GMT.

The report could not be independently confirmed by AFP.

The base is a command centre for a tactical group of Ukraine's air force.