A small but increasing number of iPhone 8 Plus owners have shared pictures of their devices burst open due to possible battery failure.

iPhone 8 Plus with display popped out via MacRumors reader Anthony Wu

MacRumors reader Anthony Wu‏, from Toronto, Canada, said he bought and unboxed a new iPhone 8 Plus on Sunday, but he was forced to return it by Monday after the display popped out. The damage was presumably caused by a defective battery inside the iPhone that swelled and placed pressure on the assembly.

We also received a similar photo today of an iPhone 8 Plus with the display burst open from iRepair, an iPhone, iPad, and Mac repair shop in Greece. In this case, we're told the customer unboxed the device last night, plugged it in overnight, and in the morning it looked as it does in the picture below.

In the latter case, the customer was supposedly using only an official Apple power adapter and Lightning to USB cable.

There are now at least five cases of possible iPhone 8 Plus battery failure, following reports in Taiwan, Japan, and Hong Kong last week.

Following the first two reports, an Apple spokeswoman told MacRumors that the company is "aware" and "looking into" the matter. But the company didn't immediately respond to our request for an update on the status of the investigation. Apple routinely looks into any possible safety concerns with its devices.

With millions of iPhones coming off the production line overseas, and thereby millions of lithium-ion batteries being manufactured, it's common in the industry for there to be a very low percentage of defective units.

For that reason, five cases of suspected iPhone 8 Plus battery failure out of millions of devices probably isn't much cause for full-blown concern at this point, but we'll continue to monitor the situation to see if a larger trend develops.

By comparison, there were reportedly hundreds of Galaxy Note 7 devices with critical battery-related failures before Samsung recalled and discontinued the device. Some of the devices caught fire, as well, which posed greater safety risks that even prompted the FAA to ban the device from in-cabin use during flights.

Following a lengthy investigation, Samsung eventually admitted that the Galaxy Note 7's battery had a design flaw.

We'll update this article if Apple responds.

Update: A sixth incident of an iPhone 8 Plus burst open has been reported in China by the Oriental Daily News. (Thanks, Edwin!)