A property owner conducting a private burn-off is suspected of sparking a bushfire that threatened homes on the South Coast at the weekend.More than 150 firefighters and six aircraft are patrolling the Shoalhaven today after erratic winds fanned two fires near Burrill Lake, in the Shoalhaven region, and in the Eurobodalla.NSW Emergency Services Minister Steve Whan said part of the fire was still burning out of control, however no properties were under threat."Obviously that can change quickly if there is a wind change," he said. "In some areas we've got to still work out what the causes of these fires were, but anecdotally so far it seems that the fire around Burrill Lake was actually an escaped hazard reduction from a private property, but that has to be investigated thoroughly."He said property owners in some areas had not heeded last week's warning to avoid burn-offs in windy, dry weather. NSW Rural Fire Service (RFS) crews have conducted backburns at both sites to set up containment lines.Mr Whan said the conditions over the weekend had been difficult for fire authorities. "For a weekend late in winter, last weekend was very challenging,'' he said. "We had a number of fires around the state and one in particular around the Burrill Lake area is still burning out of control in some areas to the west of the Princes Hwy, but it is not currently threatening people's properties."He said RFS volunteers had protected threatened houses. "I saw them there yesterday, they had tankers interspersed amongst the houses which were threatened,'' Mr Whan said. "They were standing side by side with residents who had decided to stay and fight and as a result of that the bulk of property which was threatened was saved."