New York City’s transit authority is warning travelers from using Samsung Galaxy Note 7s while on the subway or a bus. The warning comes days after reports of a six-year-old boy in Brooklyn suffering injuries from a Galaxy Note 7, which has since been identified to be a different Galaxy device. 

“MTA customers are urged not to use or charge their #Samsung Galaxy Note 7 mobile device on trains and buses,” said the Metropolitan Transportation Authority (MTA) on Twitter.

The MTA did note; however, that no Galaxy Note 7s have exploded on subways or buses thus far. “No reported cases of #GalaxyNote7 igniting on MTA property, but customers and employees should avoid using them," said the MTA in a tweet.

In the past, the MTA has banned gadgets that posed the risk of exploding. Earlier this year, the transit authority prohibited the use of hoverboards—whose lithium-ion batteries also made headlines for spontaneously combusting—from New York City's subways, trains, and buses. Part of the reason for the ban was "the safety risk of bringing devices that pose fire hazards into the confined spaces," said MTA chief safety officer David Mayer at the time.

Unlike the hoverboard, the MTA has not banned Galaxy Note 7s. For the time being, the transit authority is asking owners of the device to power down their smartphones before entering a subway station or getting on a bus. “MTA customers should turn off #Samsung Galaxy Note 7 before entering station or boarding bus due to concerns device's battery can ignite” said the MTA on Twitter.

The MTA warning, in theory, should be a non-issue since Samsung has recalled 2.5 million devices after 35 cases of Galaxy Note 7s overheating or exploding around the globe. In accordance with the recall, all owners of a Samsung Galaxy Note 7 should have swapped their smartphone for a different model or receive a loaner phone while they wait for new batch of Galaxy Note 7s.

The MTA advisory follows the Federal Aviation Administration warning for airline passengers "passengers not to turn on or charge these devices on board aircraft and not to stow them in any checked baggage." In the U.S., the Consumer Product Safety Commission has urged users to “power them down and stop charging or using the device.”

The exact cause of the malfunctioning smartphones is a production error, according to Samsung's preliminary findings. In a recent report to the Korean Agency for Technology and Standards, the South Korean company cited a battery production malfunction at Samsung SDI Co.—the company’s primary battery supplier—while also stating that “the exact cause” is to be determined.