 Mardonius then sought to break the stalemate by sending his cavalry to attack the passes of Mount Cithaeron; this raid resulted in the capture of a convoy of provisions intended for the Greeks.Two more days passed, during which time the supply lines of the Greeks continued to be menaced.Mardonius then launched another cavalry raid on the Greek lines, which succeeded in blocking the Gargaphian Spring, which had been the only source of water for the Greek army (they could not use the Asopus due to the threat posed by Persian archers).