Leaked images of Lumia 730, aka Superman, alongside a new 4G-enabled Lumia 735, are making the rounds.

Microsoft, the largest software company, is widely expected to launch new smartphones at a pre-IFA 2014 event, the Lumia 730 and Lumia 830. But according to new online reports, a third variant in the Lumia series is likely to join them. In a set of leaked images on China's social networking site, Baidu, Lumia 730 was pictured alongside its 4G variant, the single SIM Lumia 735. The leaked photos offer the best view of the upcoming mid-range smartphones.

Microsoft has built the new smartphones based on its signature Lumia design. With a thin polycarbonate unibody construction, the Lumia 730, aka "selfie phone," looks like it draws cues from its predecessor Lumia 720 and the original Lumia 800. The Lumia 730 is a dual-SIM 3G variant and the Lumia 735 offers same specs with support for upgraded LTE connections. This is the first time the 4G variant of the Lumia 730 has been spotted in leaked images.

Based on the handset's design, the upcoming smartphone does not bear any physical buttons for Back, Search and Start functions. Like other Windows Phone smartphones in the Lumia series, the Lumia 730 and 735 boasts on-screen soft keys and lacks a dedicated camera button. The mid-range smartphone is expected to have more focus on the camera capabilities, sporting a 5-megapixel front facing camera for great selfies, GSM Arena reported.

Previous reports have also revealed other technical specifications of the handset, such as a 4.-inch 720p display, 1GB RAM, Qualcomm Snapdragon 400 chipset with a 1.2 GHz quad-core processor, 8GB internal storage and a 2,000mAh battery.

The 3G version of the Lumia 730 is expected to retail around $240, GSM reported, while the pricing of the 4G model remains unknown. The smartphones were pictured in black and white colors, but the tech site expects more hues to join the new model.