Colombian President Gustavo Petro has bypassed legislative opposition and signed a decree summoning voters to the polls in August to decide changes to the country’s labor laws, including whether workdays should be limited to eight hours.

A series of attacks has plunged two southwestern regions of the country into mourning, leaving at least eight dead on Wednesday. No group has claimed responsibility, but authorities suspect the armed group Estado Mayor Central.

At least four people were killed in Colombia on Tuesday as rebel groups detonated bombs near police stations in the city of Cali and the neighboring Cauca province,

An assassination attempt on presidential candidate Sen. Miguel Uribe Turbay shook Colombia on Saturday, reviving painful memories of the political violence that has scarred the nation.

The brazen attack, captured on video, recalled the political violence of past decades. The senator arrived at a hospital in critical condition.

"America will not back down when it comes to defending its national ... tension has complicated travel between the two countries, raising safety concerns for both Americans and Colombians ...