In Mexico, an employee of the United States consulate in the northern border city of Cuidad Juárez has been shot dead. In a separate incident elsewhere in the city, a US woman who also worked in the consulate was killed with her husband as they were out walking with their baby. The baby was unharmed.

Precise details are still unclear, but what is known is that the killings happened in a city that has for years been the scene of murderous violence between drug gangs. Last year, that violence claimed the lives of 2600 people.

US President Barack Obama said he was both "sad and outraged" at the shootings and that he would do all he could to help the Mexican authorities bring the killers to justice.

The US State Department has told the employees of its six consulates in northern Mexico that they may take their families to safer locations.