Baltimore police officers tackle and arrest looters after they emerged from a "Deals" store with merchandise during clashes between rioters and police in Baltimore, Maryland April 27, 2015. Maryland Governor Larry Hogan declared a state of emergency and activated the National Guard to address the violence in Baltimore, his office said on Monday. Several Baltimore police officers were injured on Monday in violent clashes with young people after the funeral of a black man, Freddie Gray, who died in police custody, and local law enforcement warned of a threat by gangs. REUTERS/Jim Bourg TPX IMAGES OF THE DAY