SINGAPORE - A second Zika cluster has been reported at Serangoon North Avenue 1, the National Environment Agency (NEA) said on Friday (Aug 4).

Four cases of locally transmitted Zika virus infection were confirmed at blocks 109, 115 and 116 at Serangoon North Avenue 1, with all four involving residents in the vicinity.

The NEA was notified of the cluster on Friday, and has extended ongoing vector control operations in the vicinity to this new cluster area.

Last week, the first Zika cluster, with three cases, at Serangoon North Avenue 1 was reported.

NEA has been conducting preventive inspections - to detect and destroy potential mosquito habitats - in the vicinity right up to the discovery of the new cluster area.

Zika information leaflets and insect repellent are being distributed to households to raise awareness of Zika and emphasise the importance of preventing mosquito breeding.

NEA is also continuing with vector control operations and outreach efforts in the cluster area at blocks 125, 126 and 127.

As of Thursday (Aug 3), it has inspected more than 940 premises in the first cluster area. A total of nine breeding habitats had been found and destroyed in the area, of which six were from homes, and three in common areas.

NEA said residents are advised to apply mosquito repellent as a precaution. It urged residents to cooperate with NEA officers by allowing them to carry out inspections and indoor spraying of their homes.

"Most people infected with the Zika virus do not develop symptoms, which heightens the risk of a Zika resurgence as it may take some time before a reintroduced Zika virus is detected," NEA said.