Children were left terrified after yobs rode through their football match on scrambler and electric bikes, threatening to "slice people's throats".
A senior police officer has said it was "through sheer luck" that nobody was hurt.
At around 6.40pm on Thursday (April 22), two men are said to have entered the playing fields at Buckley Hill in Netherton.
One parent wrote on Facebook : "They rode straight through the football match, nearly hitting the kids whilst giving abuse to parents and threatening to slice peoples throats.
"They continued to taunt other people on other pitches before police arrived and then they disappeared."
Merseyside Police confirmed reports two men riding a scrambler bike and electric bike onto football pitches, of threats being made, and the bikes being ridden close to children playing on the pitches.
No injuries were caused, and the bikes were ridden off in the direction of the cemetery.
Officers are appealing for information, and say enquiries are ongoing.
Sefton Inspector Ray Mavrakakis said: “This was an appalling incident where two bikes were ridden dangerously, causing risk and understandable distress to those children enjoying their football, and their parents and coaches nearby.
"Threats were also made when the riders’ behaviour was challenged, and it is through sheer luck that nobody was seriously hurt.
“We have seen the devastation that scrambler bikes and other dangerous driving can cause in our communities so if you witnessed this incident, captured any footage or images or hold other information, please come forward and we will take action to put those responsible before the courts.
“All of our communities are safer when one of these bikes is seized, and we will continue to take proactive measures against those who cause fear, distress and serious incidents.
“If you know where bikes are being stored, either in homes, storage units or elsewhere, please come forward and we will act on all information provided.”
Anyone with information on this incident can contact Merseyside Police social media desk via Twitter @MerPolCC or by searching "Merseyside Police Contact Centre" on Facebook, with reference 21000258486.
You can also call 101 or contact the independent charity Crimestoppers anonymously on 0800 555 111, or via their website here
Always call 999 if a crime is in progress
