Armed Australian police arrested seven men in Sydney's southwest after a tip they may be plotting a "violent act" in the city still reeling from the Bondi Beach shooting.

"At this point in time, police have not identified any connection to the current police investigation of the Bondi terror attack," New South Wales state police said in a statement.

Police said special tactics officers intercepted two cars after receiving information "that a violent act was possibly being planned".

Armed police in camouflage gear searched several men as they lay face down on the road with their hands zip-tied behind their backs, according to footage obtained by local media.

One of the suspects appeared to be bleeding from a gash on his head.

A police SUV had rammed head-on into a small white hatchback driven by the suspects.

"As investigations continue, seven men are assisting police with their inquiries," police said.