Newton Police are investigating after gathering dozens of thumbtacks in a bike lane.
Police say they gathered the tacks along Nahanton Street in Newton on Saturday after a cyclist blew a tire.
The incident isn't a first in the area, as thumbtacks were discovered in a bike lane one other time in the last month.
Now, cyclists and police are worried for any future incidents.
"I don't want to get any flat tires," Saya Ameli, a cyclist, said. "That's just, that's not right."
Newton Police say a group of cyclists found 30 to 40 thumbtacks in the lane, and Lietuenant Bruce Apotheker say the other incident last month took place on Winchester Street.
"It's very concerning to us, because if someone's driving a bicycle, that bicycle could tip over and they could get injured," Apotheker said. "If someone's running in the roadway, a thumbtack could go through a sneaker."
Apotheker said the incident was clearly malicious, given the fact that it wasn't a one-time occurrence.
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"If this was the first time, you know, we would say 'Maybe somebody dropped them out of the window by accident,'" Apotheker said. "But this is more than once now."
Now, police are hoping the community will help them find the person responsible.
"It can be pretty dangerous too," Ameli said. "If you’re going down this hill, you’re going pretty fast. Then suddenly your tire gives out, you’re probably going to end up crashing."