Foo Fighters have announced their comeback by posting a picture of a blood-spattered guitar on their Facebook page. The image was taken by frontman Dave Grohl and was tagged with the caption: “First practice. Been too long. Look out, Mexico.” The pic was snapped as the band prepared themselves for their comeback to touring next month in Mexico. The band will perform a headline show at Mexico City’s 55,000-capacity Foro Sol stadium on December 13, with the National opening. Foo Fighters’ last gig was in New York in September 2012 at the Global Festival event. Grohl recently confirmed that the band is recording a new album, the follow-up to 2011’s Wasting Light