The first Zika cluster of the year was reported yesterday.
The cluster, in Simon Place, involved two locally transmitted cases from the same household.
Residents of the area, which is near Kovan in Hougang, have been informed to stay vigilant.
The authorities started vector control operations on Tuesday.
Zika, which affects the development of unborn babies, surfaced in Singapore last August. The last cluster, in Bedok North Street 3, was closed in December last year. It had seven cases.
As of yesterday, the National Environment Agency has inspected about 120 out of some 400 premises in Simon Place.
Ten breeding spots were detected and destroyed.
Six other isolated Zika cases have been reported this year.
SEE TOP OF THE NEWS: First Zika cluster of 2017 reported in Simon Place