A new Zika cluster of two cases has been confirmed in the Flower Road/ Hendry Close area - the second such cluster found in a fortnight.

The new cluster is near Simon Place where, last week, the authorities said two people from the same household had contracted the mosquito-borne disease, forming this year's first cluster.

In a statement yesterday, the National Environment Agency (NEA) said the two new cases are residents in the area, where mosquito-control operations are already ongoing.

NEA urged people living there to continue to remain vigilant and destroy any mosquito-breeding habitats they find.

"There could still be asymptomatic or mild, undiagnosed cases, which might result in further transmission of the virus if there are mosquitoes in the vicinity," said the statement.

Infectious diseases expert Leong Hoe Nam said it is difficult to translate the significance of the four cases in and around Simon Place.

"Assuming that they are not related to the first couple, the cluster may be a cause for concern," he said.

However, he added that doctors practising in the area may also simply be more alert to potential Zika patients, and hence more likely to pick them up.

"Still, I would caution pregnant women to avoid the area," said Dr Leong. "If they have to go there, they should wear long sleeves and put on insect repellent."

NEA urged residents to allow its officers into their homes to carry out inspections and indoor spraying.

"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," it said yesterday.

One Hendry Close resident, 54-year-old Constance Chan, said that since she heard news about Zika cases in Simon Place, she has been taking extra precautions.

The businesswoman said in Mandarin: "I used to collect rainwater in pails, for washing the floor and watering the plants, but I stopped doing this. I'll also spray the dark corners with insecticide."