BOGOTA, Colombia — A bomb blew up outside an upscale nightclub in southwestern Colombia on Sunday, killing at least 11 people and wounding 48. The attack cast new doubt on President Alvaro Uribe's promises to crush a 39-year rebel insurgency.
The bombing was blamed on leftist rebels and appeared to be part of a nationwide campaign of violence aimed at thwarting regional elections scheduled for Oct. 25. Rebels have assassinated politicians, disabled rail and communication links and blown up bridges.
"Colombia is in tears but will not give in," Uribe said on a visit to the coastal city of Santa Marta, where officials observed a minute's silence in memory of the dead. "The only path for us is to defeat terrorism and we must persist."
Revelers were heading home after a Saturday night out at the popular Bar Rosa in Florencia, 235 miles southwest of the capital Bogota, when the bomb went off. The device was attached to a motorcycle and sent debris flying into the air, shattering windows and cutting down passers-by.
"This is an indescribable act of terrorism," said Florencia police chief Rafael Parra. "The bomb clearly targeted the civilian population." He blamed the attack on the Revolutionary Armed Forces of Colombia, or FARC, and offered $17,500 for information leading to an arrest.
The wounded overwhelmed the city's only fully equipped hospital. Officials appealed for blood donations.
"This is a small city that does not have the infrastructure to treat so many injured," Parra said.
The dead included a 9-year-old child and two police officers.
"I had been partying with office colleagues and was waiting for a taxi when the explosion occurred," an unidentified victim, suffering from burns to her face and arms, told RCN television from a hospital bed in Florencia. "Everything was thrown into the air, everybody was screaming."
Security forces have responded to recent attacks by carrying out mass arrests of thousands of suspected rebel fighters, leading to the seizure of several arms caches.
The vast of majority of killings by rebels have occurred in poor villages in the countryside, while Colombia's major cities have been mostly spared from the worst of the violence until recently.
But Sunday's attack — along with a February bombing in Bogota that killed 36 people — underscored the government's inability to safeguard affluent neighborhoods more than a year after Uribe took over as president on pledges of restoring the state's authority and defeating the rebels. The insurgents have waged war for 39 years, and about 3,500 people die each year.
Defense Minister Martha Lucia Ramirez visited Florencia and held two hours of emergency meetings with security officials. She appealed for national unity, saying "together we can put a stop to these sorts of terrorist acts."
She said at least 11 were killed and 48 wounded.
Helped by millions of dollars in military aid from the U.S. government, Uribe has launched all-out war on the rebels. Despite the violence, he has seen some success. Cocaine production, for instance, which finances the rebels and outlawed right-wing paramilitary groups, dropped by one-third in the first seven months of this year, according to a U.N. report.
On Monday, Uribe is due to travel to Washington to secure pledges for continued military aid. He will then deliver a speech at the U.N. General Assembly in New York.
Uribe's campaign to restore order in this South American country suffered another setback two weeks ago when gunmen, believed to be members of the National Liberation Army, or ELN, kidnapped eight foreign tourists from archaeological ruins in the Sierra Nevada mountains of northern Colombia.