At least 13 MPs from the People's Action Party (PAP), including Minister in the Prime Minister's Office Chan Chun Sing, have had fake Facebook accounts created in their names.
Most appeared between Thursday night and yesterday, bearing the MPs' names, profile photos and banner photos in the background.
They were deleted shortly after the MPs were alerted to them by grassroots leaders and residents.
The PAP's communications team had also been told of the spate of fake accounts, "about two to three daily", MP Alex Yam, who is the PAP's executive director, said in a Facebook post yesterday.
The fake accounts mirrored those of the MPs, added friends, then tried to phish for information through Facebook's messaging service, he added.
Mr Yam urged users to look for a blue tick - Facebook's symbol of verification - on MPs' profiles, and alert the MPs if they come across suspicious accounts.
Ms Tin Pei Ling, a victim of the deception, gave her residents a quick lesson on Facebook yesterday on how to spot fake accounts.
Besides the absence of a blue tick against her name, the impersonator had asked her Facebook friends to go into what appears to be a scam site, she wrote.
A screen shot of the fake account shows the impersonator had contacted one of Ms Tin's contacts, saying: "I really appreciate everyone and will continue to serve you in taking this great singapore (sic) to the greatest place we ever desire."
The imposter then asked if the contact had ever heard of the "FB reward bonus" and if he wanted the link to claim the reward.
Ms Tin told The Straits Times: "I don't sound like this. This sounds like a phishing message."
Mr Chan, who is also the labour chief, said that while the motives behind the accounts could be varied - from having fun to criminal intentions - "we have a responsibility to stop imposters".
"Do not accept requests to connect if you are not sure. Keep safe online. Imitation is not always the best form of flattery," he said in a Facebook post yesterday.
Parliamentary secretary Baey Yam Keng, who was also affected, said the sudden spate of attacks may prompt the MPs to take collective action. "We'll see whether we can work with Facebook to see if the fake accounts are coming from the same IP address, and make a move from there."
The other affected MPs were Deputy Speaker Charles Chong, Senior Ministers of State Heng Chee How and Sim Ann, Minister of State Chee Hong Tat, Dr Lily Neo, Dr Chia Shi-Lu, Mr Ang Wei Neng, labour MP Desmond Choo, Ms Cheryl Chan and Mr Darryl David.
This is not the first incident of fake social media accounts to hit PAP MPs.
Last June, Minister of State Koh Poh Koon warned residents of a fake Twitter account in his name that was promoting an online coupon site and an education site.
In 2015, a scammer created a fake Facebook profile of Speaker of Parliament Halimah Yacob, saying she (Madam Halimah) was in trouble and needed money, and asked friends to transfer money to her.
In 2014, a Facebook account in labour MP Zainal Sapari's name was set up to ask for money.
Mr Yam told The Straits Times his communications team regularly monitors the social media accounts of branch chairmen and reports suspicious accounts .
But the latest spate, he said, is a little more concerted as new fake profiles "are set up as old ones are taken down".
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