Images of an unannounced Sony D6503 handset leaked online over the weekend, showing a device that looks like an updated version of the Sony Xperia Z1.

Sony has recently unveiled its new Xperia Z1 Compact powerhouse, as well as the T-Mobile-exclusive Xperia Z1S, but has made no mention so far of this newly-leaked model. The Xperia Z1S for T-Mobile is already a slightly upgraded version of the Xperia Z1, so it remains unclear for now what the company plans with this new model. One possibility could be that the new Sony D6503 is an Xperia Z1 version for other U.S. carriers, as the Z1S is exclusive to T-Mobile, but nothing is confirmed at this point.

The images showing this purported Sony D6503 come from XDA Developers user iRimas, who posted several photos of the handset with the mention "UI Coming Soon." At a first glance, the leaked handset looks very much like an Xperia Z1 refresh.

The device shown in the photos (see above) seems to have smaller bezels around the display, which could mean a 5.2-inch screen. There are also some minor changes, such as larger speaker holes at the bottom of the handset, as well as a SIM tray that appears to be relocated on the left side of the device. The images further show that the smartphone may sport a microSD card slot on the side.

Other than these small changes, the power button, volume rocker, camera key, headphone jack, magnetic pins, and the LED notification light all seem to remain unchanged, exactly where they are on the original Xperia Z1. The camera is also placed in the same spot on the back of the handset.

The original Sony Xperia Z1 sports a 5-inch full HD 1080p Triluminos display with the company's X-Reality technology. It packs a quad-core Qualcomm Snapdragon 800 processor clocked at 2.2GHz, 2GB of RAM, and 16GB of internal storage capacity, with a microSD card slot for additional memory. The smartphone is 4G LTE-enabled, has a large 3,300 mAh battery and is dust- and water-resistant.

Specs for this Sony D6503 device are yet to surface, but if it is indeed an Xperia Z1 refresh it should sport some notable improvements. Until Sony makes it official, however, take things with a grain of salt. With the Mobile World Congress (MWC) 2014 just around the corner, Sony might make an announcement soon.