Edinburgh and Glasgow Warriors have launched women's teams for the first time to compete in an expanded Celtic Challenge that will also feature new sides from Ireland and Wales.

Its Welsh counterpart has created two new teams - Brython Thunder, playing at Parc y Scarlets, Llanelli, and Stadiwm CSM in Colwyn Bay, and Gwalia Lightning based at Cardiff Arms Park.

The Celtic Challenge was piloted with three teams in January 2023, with the aim of bridging the gap between women's domestic and international matches.

An expanded version kicks off on 29 December as Wolfhounds host Clovers in one of three derby games over the New Year period.

Warriors travel to Edinburgh's Hive Stadium the following day, with the game finishing shortly before the respective men's sides kick off in their United Rugby Championship derby at next-door Murrayfield.

Thunder face Lightning on New Year's Day at a time and venue yet to be decided.

Scottish Rugby head of women and girls' strategy Gemma Fay said the decision to align its new teams with Edinburgh and Glasgow is "a fantastic opportunity to provide our two teams with a strong individual identity and sense of belonging, whilst also tapping into each club's current fan base".

Ireland's two sides will play their home games at Munster's Musgrave Park, Leinster's Energia Stadium and Ulster's Kingspan Stadium.

IRFU head of women's performance and pathways Gillian McDarby told her union's website: "The collective goal of the three unions is to elevate the Celtic Challenge to the highest level of competition possible, ensuring that players are in the best position to compete in the Women's Six Nations."

WRU head of player development John Alder said its two franchises "will play across the country in north, south, east and west Wales in acknowledgment of the growing demand to engage with women's rugby" around the principality."

The Celtic Challenge will be made up of five rounds before three double-header play-offs determine who will be this season's champions in March.