The four-piece appeared to be teasing an official get together with a black and white photo of the top of their heads as they look up at a huge '2016' sign, which was posted on social media on New Year's Day (01Jan16).

Melanie Blatt, Shaznay Lewis, and sisters Natalie and Nicole Appleton haven't released any new material since 2006's Studio 1 album. The quartet enjoyed success throughout Europe with their debut album in 1997.

They reformed for a series of concert dates with Backstreet Boys and a handful of U.K. festival dates in 2014.