Adelaide, Jun 23 (IANS): Heavy rain have caused flooding and blackouts in the state of South Australia (SA), prompting hundreds of calls for aid.

Adelaide and its surrounds were battered by a heavy thunderstorm on Thursday night, with the state capital receiving 41.6 millimeters of rain as of Friday morning, reports Xinhua news agency.

More than 2,800 households and businesses were without power on Friday morning and the State Emergency Service (SES) had responded to 240 calls for assistance including swift water rescues after people became trapped by rapidly rising floodwaters.

Roads have been closed in some areas and motorists were warned not to drive through floodwaters.

"We're just asking commuters to plan their travel, it's never safe to drive into floodwaters so please make sure you find an alternative route if you are faced with that," Dave O'Shannessy from the SES told Australian Broadcasting Corporation (ABC).

More than 100 SES volunteers have been called upon for flooding assistance.

A private dam east of Adelaide broke its banks and created a road hazard but is structurally sound.

"Although the forecast for today sees the showers clearing we do anticipate there still will be some flooded roads and debris on the roads," O'Shannessy said.

Conditions were forecast to ease significantly on Friday after the main system driving the heavy rain passed into Victoria but showers are expected to persist.

"Thankfully the worst of it has passed," Bureau of Meteorology senior forecaster Mark Anolak said.