The war opened in the Balkans when Russian troops occupied provinces in modern Romania and began to cross the Danube. Led by Omar Pasha, the Ottomans fought a strong defensive battle and stopped the advance at Silistra. A separate action on the fort town of Kars in eastern Turkey led to a siege, and a Turkish attempt to reinforce the garrison was destroyed by a Russian fleet at Sinop. Fearing an Ottoman collapse, France and the UK rushed forces to Gallipoli. They then moved north to Varna in June, arriving just in time for the Russians to abandon Silistra. Aside from a minor skirmish at Constanța there was little for the allies to do. Karl Marx quipped that "there they are, the French doing nothing and the British helping them as fast as possible".