Live updates: Three police officers shot dead in Baton Rouge
- Three police officers have been shot dead in Baton Rouge, Louisiana
- The gunman, named as ex-marine Gavin Long, has been shot and killed
- He had posted videos online complaining about the police treatment of African-Americans
- Surveillance photos have been released showing Long 'intentionally targeting' police and he had scoped out areas to carry out his attack
- US President Barack Obama has called on his country to unite and avoid divisive language
- Our Washington correspondent said America is facing a racial division that is spiralling out of control
