They had heard and read about the wild boar attacks at nearby Punggol Walk last Saturday and were already concerned.
When a video of a wild boar running into the condo's premises started circulating later, a number of residents at A Treasure Trove condominium became a little more agitated.
A resident, who wanted to be known only as Mr Tan, told The New Paper yesterday: "I think everyone here is worried. We thought boars will only roam forested areas, not buildings or condos. In fact, my in-laws called me and reminded me not to cycle so late (at night)."
The 45-year-old, who works in information technology, said the video had been circulating on a Facebook group for residents since Monday.
It showed the animal walking along a road divider outside the condo and then trying to get across to one side, stopping traffic, before dashing across to the opposite side and slipping through the gate of the condominium, which was open to allow a car to exit.
"If I am not wrong, this video was taken a couple of hours before the Punggol HDB attacks. Not sure if it is the same boar but I guess it has to be," said Mr Tan.
At least three people were injured in separate attacks last Saturday. The first occurred at 308B Punggol Walk at 9.10pm, where a woman was dragged for a metre by a wild boar and had to be taken to Singapore General Hospital (SGH).
The second attack happened about 10 minutes later at Block 310B and an eyewitness said the victim sustained scratches and subsequently took a taxi to SGH.
The third attack took place at Block 310A at 9.30pm and one person was taken by ambulance to SGH.
It is not clear if the same boar was behind all three attacks.
On Monday, the NParks said that a team of 20 officers and contractors had been activated to patrol the area and search for the wild boar.
MP for Punggol West SMC Sun Xueling said in a Facebook post on Monday that she met the NParks team and contractors during a Meet-the-People session, and they would patrol the Punggol area until 3am yesterday.
TNP understands that the wild boar is still at large and patrols are continuing.
Ms Gitta Priska, a 22-year-old university student, lives at A Treasure Trove with her family.
She suspects the boar responsible for the attacks was the one that entered the condo earlier that day.
She said: "It is a bit concerning, and my parents keep warning me to keep a lookout when I am out at night."
One condo resident is taking it in her stride though.
Ms Connie Chin, a 59-year-old accountant, said she is not afraid as she believes wild boars always run about.
"I jog regularly with my husband and we (were) never too concerned (about this). All I know is the boar is no longer in the condo," she said.
This article was first published in The New Paper.