A flood control dam in Austria has burst, sending floodwaters into the town of Stillfried.

Firefighters and army troops have been working to patch the 50m gap with sandbags, and a Blackhawk helicopter has been sent in to help with rescue work in the town, which is 40km northeast of Vienna.

Thirty homes were evacuated overnight in Stillfried, which is downstream from the village of Duernkrut, where the river March partially gave way on Monday, forcing some residents there to be evacuated.