NSW and Australian Federal Police have carried out raids on several Sydney homes, including one of the properties targeted during large-scale counter-terrorism raids in September.

A police spokesman confirmed "members from the joint counter-terrorism team in Sydney conducted a number of search warrants on Thursday" as part of an ongoing operation, but said the action was not connected to Monday's Martin Place siege.

"The search warrants were executed on five residential premises in the Sydney suburbs of Marsfield, Regents Park, Wiley Park, Georges Hall and Condell Park," the spokesman said.

"The purpose of those warrants was to seek additional information in relation to the ongoing Operation Appleby.

"At this stage, no charges have been laid as a result of those search warrants."

It is also understood that at least one of the properties was targeted during large-scale counter-terrorism raids in September.