Nokia's Lumia product line makes a public visit every now and then and the latest has hit the web showing off a fresh set of images of two of its Windows Phone 8 devices - the Lumia 520 and Lumia 720.

Both the devices are expected at the Mobile World Congress (MWC) later this month and the leak that comes just before its imminent launch has been brought out through the Twitter account of evleaks, a fairly reliable source of leaked press images of unannounced phones.

Nokia Lumia 720 and Lumia 520, otherwise named Zeal and Flame respectively, will come in same bright colors such as cyan, yellow, red, white, and black with some bubbled-up specs. As Unwired View notes, "The 720 and 520 will come as successors to the Lumia 710 and Lumia 510 (which run Windows Phone 7.x, and won't be updated to WP8)."

Although there is no mention about the specifications of the devices with the current leak, past rumors suggest that Lumia 720 would be a mid-tier smartphone while Lumia 720 will be more of an entry level handset. As we have reported earlier, Nokia Lumia 720 is expected to come with a 4.3-inch display with Nokia's ClearBlack glare-reducing filter, 1GHz dual-core processor, 8GB of internal storage, 512MB of RAM, 6-megapixel rear camera and 2-megapixel front camera. The device will support HSPA+ networks, run on Windows Phone 8 and have a microSD slot for expansion.

On the other hand, Nokia 520 has been rumored to be an ultra-cheap WP8 handset featuring a 4-inch super-sensitive screen, 1GHz dual-core processor, 8GB of internal storage, 512MB of RAM, and a 5-megapixel rear camera. The handset will not have a front-facing camera. It will run on Windows Phone 8 and would include a microSD slot for memory expansion.

These are not the only devices expected to see official launches at the mega tech event in Barcelona later this month. The Finnish mobile phone maker would release a successor to its Lumia 920 at the event along with its Lumia 1000 PureView.

Lumia products beginning with the number 5 are considered to be the most economically priced smartphones from Nokia while handsets beginning with the number 9 are considered to be Nokia's high-end offerings.