Minister of Communications and Information Yaacob Ibrahim said on Wednesday night that his naming of a blogger and a website for circulating online rumours during the recent haze was to be fair to the majority of the online community.
Otherwise, they may be inadvertently associated with spreading rumours, he added in a posting on Facebook.
In Parliament on Monday, the minister had cited many examples of Singaporeans pulling together and using the Internet to do good and clarify doubts.
But he also warned that some mischievous individuals had set out to spread rumours and cause unnecessary anxiety.
The five examples he cited included The Real Singapore putting up an article falsely attributed to Tampines GRC MP Irene Ng.
Another was blogger Ravi Philemon, who posted online that the public would not be able to access a fresh supply of masks that were arriving in Singapore.
Dr Yaacob recounted the sequence of events in his Facebook post.
On June 21, the Government announced that 1 million N95 masks would be distributed to 200,000 low-income households for free, and that the Singapore Armed Forces will help give out the masks.
The next day, on June 22, Mr Philemon posted an unnamed friend's claim that the supply would be strictly controlled by the Government, Dr Yaacob noted.
The minister said: "The upshot of Ravi's post is that the Government announcement the day before is not true. But what is his basis for suggesting so? The truth is, he had no basis for his assertion."
As to Mr Philemon saying later that he went to Johor Baru to buy N95 masks when they were sold out at pharmacies here, to give to others, Dr Yaacob said he was "happy to learn" that the blogger had distributed some masks to the community.
"But let's be clear," he added, "doing good offline does not mean one is excused from acting responsibly online."