Washington, DC (CNN) The scooter-sharing startup Lime continues to clash with its suppliers amid questions about the safety of its scooters.

Chinese company Okai is pushing back on claims that it's the source of flawed Lime scooters.

Earlier this month, Lime said it removed all of its scooters manufactured by Okai following reports that the baseboard where users stand can snap in half and endanger riders.Some riders have suffered injuries, and an Okai scooter may have contributed to a fatality. Lime uses scooters from multiple manufacturers, but doesn't reveal exactly how many.

In late October, Lime stated the baseboard on its Okai models could break if ridden off a curb at high speeds.

Okai said Friday Lime's claims are "groundless" and the faulty scooters come from another supplier.

"We feel it necessary to make cautions to the public on the credibility of such statements made by Lime," Okai said in a statement sent to CNN Business on Friday. "Obviously, Lime has other suppliers whose scooters broke."

Lime declined to comment on whether it has recalled scooters from other manufacturers.

not all looked the same. The Okai model has a distinct set of lights and screws, the manufacturer said in its statement. Photos on social media and in news reports revealed Lime scooters with broken floorboards -- some of which match images of the scooter model Okai says it provided to Lime. Butnot all looked the same. The Okai model has a distinct set of lights and screws, the manufacturer said in its statement.

Okai said it sold 32,000 scooters to Lime, but the company has not revealed how many scooters it has removed from streets. When it recalled some scooters over battery concerns earlier this year, the issue impacted less than 0.01% of its fleet, Lime said.

The company said it is working with the US Consumer Product Safety Commission to investigate its Okai scooters.

In 2017, Lime launched as LimeBike, a dockless bikesharing startup. But this year it shifted its focus to scooters after Bird, a Santa Monica startup, pioneered a popular scooter-sharing service. Lime has since raised hundreds of millions of dollars, including from Uber. Lime operates in 10 countries and more than 85 US cities.

Scooters have been shown to reduce car trips, earning praise from environmentalists and city experts. But safety questions have followed the company's rapid expansion. In September, a Dallas man died shortly after a crash while riding a Lime scooter. Police discovered the scooter was broken in half, but the company hasn't said if the man was riding an Okai scooter.

This photo, taken in October, shows several scooter models that Lime previously available in Washington DC. Okai says the scooter on the far left, and second from the right, isn't its scooter.

Along with fellow Lime supplier Ninebot, Okai is calling on scooter companies to do more to protect scooters from the wear-and-tear of daily use.

"It is the operator's responsibility to ensure proper and prompt management and maintenance of the scooters it puts into the co-sharing market," Okai said.

Lime has already taken some steps to tackle safety concerns. It announced a $3 million program to distribute 250,000 helmets and educate riders on safety practices. Lime recently unveiled a new scooter with safety improvements, such as larger wheels, intended to better handle potholes and uneven roads.

Companies are racing to meet demand and expand to new cities.

But the Silicon Valley-backed companies have grown at a breakneck pace , which has drawn criticism for introducing problems at a scale that wouldn't occur with steadier growth. Some view scooters as clutter because they're sometimes parked incorrectly, such as blocking sidewalks.

According to Tony Ho, vice president of business development at the Chinese company Ninebot, which makes a majority of the shared scooters in use worldwide, the scooter-sharing industry is so new that issues continue to pop up.

He said Ninebot plans to release a new model later this year that's better designed for harsh conditions. Shared scooters are typically ridden a half-dozen times a day on roads of varying quality, and in inclement weather. Scooters are often thrown to the ground, or tossed in the back of trucks to be charged. And minor cracks can expose components, leading to malfunctions.

"There's room to improve in how to operate, and how to train chargers," Ho said of the scooter-sharing startups. "This is almost like a new test for us. The product needs to sustain a real industrial type of environment."

Segway is also shifting the battery in its scooters to the baseboard. This will lower the center of gravity, making them less likely to tip over and expose riders to head injuries.

"It's gonna be a beast," Ho said of the new scooter.