The second alleged incident was reported to have been near Sunset Liquor, when a man was attacked by a group of "drunks".
Rotorua police Senior Sergeant Nicky Riordan, acting crime prevention manager, said it was important people reported suspicious behaviour or known crimes to police.
"There have been a few occasions recently where we have heard of incidents or concerns via a third party or through social media rather than direct reports to us," she said.
"Some of this appears to be the result of people not wanting to trouble us, as the information isn't clear cut or is just a gut feeling. We really want to encourage the community to pass this information to us.
"It may not be enough to act on or solve a problem there and then, but it might be a crucial piece of a bigger picture. More importantly, it might put us on the front foot to be able to prevent offending rather than react to it."
The man behind the social media page said he thought the victims would enact their own justice.
"Bad pricks don't report bad pricks," said the man, who wished to remain anonymous.
"They'll get back at those who have done it in their own way, which is really nasty, or perhaps because they've had a bad experience from police. Some people think police are too busy and they'll let it go, but for us to stop crime we have got to pull our fingers out and tell police. You can't take things into your own hands."