(CNN) -- Six people were killed in an explosion targeting a police station in southern Colombia Thursday, authorities said.
The blast in Villa Rica killed a police commander and five civilians, Cauca province Police Cmdr. Ricardo Alarcon told reporters. Dozens were injured.
A man who was eating lunch inside his home near the police station was among the casualties, CNN affiliate Caracol TV reported.
A car in front of the station fired gas cylinders packed with explosives Thursday afternoon, the affiliate said.
A government hospital next to the police station was badly damaged by the explosion, provincial health secretary Oscar Ospina Quintero said. Many of those injured were patients in the hospital.
"The bomb destroyed the emergency room and the maternity wing," Ospina said.
Authorities evacuated patients from parts of the hospital and relocated services to a nearby school, he said.
The blast also destroyed numerous homes and stores, Caracol reported.
Thursday's blast comes a day after a bomb exploded in neighboring Narino province, killing nine people and injuring more than 70, Caracol said.
Police were offering a reward of up to 100 million pesos ($56,000) for information leading to the capture of those behind Wednesday's attack in Tumaco, Narino.
Authorities stepped up security in the area, Colombian President Juan Manuel Santos said on a visit to that province Thursday, noting that 300 additional police had arrived since the attack.
Santos condemned the Revolutionary Armed Forces of Colombia guerrilla group for the bombing.
"They have offered as a gesture of peace the liberation of hostages. They should do that. Of course, for humanitarian reasons, we are prepared to facilitate it. But they should not be hypocrites, talking about peace on the one hand and committing terrorist acts on the other," Santos said. "No one understands this double play, this double standard. The whole world rejects it and in addition it pushes away any possibility of peace."
The leftist rebels, known as the FARC, have been at war with the Colombian government since the 1960s. While severely weakened in recent years, the guerrilla group has continued to carry out kidnappings and attack security forces.
In December, the group had announced the planned release of six national police officers, but in a statement Wednesday they said the plan would be postponed because Colombian authorities had sent too many troops to the area where they planned to release the hostages.
CNN's Rafael Romo and Edwin Mesa contributed to this report.