A worker fogs a community playground at a new Zika cluster area in Singapore, September 1, 2016. [Photo/Agencies]

SINGAPORE/BEIJING - China intensified its checks on people and goods arriving from Singapore on Thursday, as an outbreak of the Zika virus in the small city-state was confirmed to have spread to at least one person in neighboring Malaysia.

Authorities in Singapore, a leading regional financial center and busy transit hub for people and cargo, said they had detected 151 people with the Zika virus, including a second pregnant woman, as of midday Thursday. The first locally-transmitted Zika infection was reported on Saturday.

The government said earlier that half of the 115 cases reported previously were foreigners, mainly from China, India and Bangladesh, and most had already recovered. Many of them are believed to be among the hundreds of thousands of migrant workers in Singapore's construction and marine industries.

Some new Zika cases have been found beyond the cluster area where the virus was initially detected.

"We have been tracking Zika for a while now, and knew it was only a matter of time before it reached Singapore," Prime Minister Lee Hsien Loong posted on his Facebook page. "Our best defense is to eradicate mosquitoes and destroy breeding habitats, all over Singapore."

Singapore is the only Asian country with active transmission of the mosquito-borne Zika virus, which in pregnant women can lead to serious birth defects.

Malaysia confirmed its first case of Zika infection, in a woman who had recently visited Singapore.

The United States, Australia and other countries have added Singapore to the growing list of places that pregnant women or those trying to conceive have been warned to avoid.