Colombia was hit by a wave of 24 coordinated bomb and gun attacks that left at least seven people dead and 28 injured across the southwest of the country, deepening a growing security crisis.

The attacks targeted Cali — Colombia’s third-largest city — and several nearby towns, striking police posts, municipal buildings and civilian areas.

National Police chief Carlos Fernando Triana said on Tuesday the attackers, suspected to be a local rebel faction, used car bombs, motorcycle bombs, rifle fire and a suspected drone. "There are two police officers dead, and a number of members of the public are also dead," he said.

The attacks came just days after a failed assassination attempt on a presidential candidate in Bogota, further raising tensions. Many Colombians fear a return to the violence of the 1980s and 1990s, marked by cartel bombings and rebel attacks.

In Cali and the towns of Villa Rica, Guachinte and Corinto, journalists saw wreckage of vehicles and damaged buildings. In Corinto, resident Luz Amparo said her bakery was destroyed: "We thought it was an earthquake," she told AFP news agency. "My husband said 'no, they are shooting.'"

Police and experts believe the attacks were carried out by the Central General Staff (EMC), a dissident faction of the former FARC rebel group. Elizabeth Dickinson of the International Crisis Group called it "a particularly well-coordinated offensive" and warned it demonstrated the group’s growing operational capacity.

Efforts by President Gustavo Petro to negotiate peace with the EMC have repeatedly failed. Analysts say the group may be responding to a military operation that reportedly injured or killed its leader, known as "Ivan Mordisco".

Meanwhile, a 15-year-old pleaded "not guilty" to the attempted assassination of Senator Miguel Uribe, who was shot in Bogota last week. President Petro suggested the attack was ordered by an international "mafia" and criticised the reduction in Uribe’s security on the day of the shooting.