The French, German and Russian foreign ministers on Monday held closed-door talks in Paris over the Ukraine crisis, a German foreign ministry official said.

The French, German and Russian foreign ministers on Monday held closed-door talks in Paris over the Ukraine crisis, a German foreign ministry official said.

There were, however, no details of the discussions between France's Laurent Fabius, Germany's Frank-Walter Steinmeier and Sergei Lavrov of Russia after a giant international conference on fighting ISIL militants in Iraq.

Steinmeier's spokesman and a French diplomatic source confirmed the talks.

Ukrainian forces and rebels engaged in heavy fighting on Sunday in which six people were killed, despite a truce signed on September 5.

The warring sides signed up to a 12-point ceasefire after talks in the Belarussian capital Minsk -- the first truce backed by both Kiev and Moscow -- but there have been almost daily reports of violations.