Colombia's president says rebels may be behind surprise bomb blasts in capital

Colombia's President Juan Manuel Santos listens in during the closing ceremony of the Business Summit in Paracas, Peru, Thursday, July 2, 2015. The Business Summit of the Pacific Alliance is taking place on parallel with the 5th Presidential Pacific Alliance Summit which starts on Friday. (AP Photo/Rodrigo Abd) (The Associated Press)

Colombia's President Juan Manuel Santos is seen reflected on a sheet of glass as delivers a speech during the inauguration of the Presidential Pacific Alliance Summit in Paracas, Peru, Thursday, July 2, 2015. (AP Photo/Rodrigo Abd) (The Associated Press)

BOGOTA, Colombia – President Juan Manuel Santos said Friday that Colombia's second-largest rebel group is likely to blame for two bomb blasts in the capital that wounded 10 and rattled city residents who have become unaccustomed in recent years to such acts of violence.

The homemade explosives were detonated Thursday outside two offices of local pension fund Provenir, one of them a branch in the heart of Bogota's ritzy financial district,

Santos, after a meeting with top security officials, said that preliminary investigation points to the National Liberation Army, or ELN, but presented no evidence to back up the assertion. Authorities have said the group is responsible for seven explosions in less-conspicuous parts of the capital over the past year.

He said the attackers may have been seeking to torpedo peace talks taking place with the larger Revolutionary Armed Forces of Colombia, negotiations which the ELN has been invited to join.

"I don't know what the people launching these explosives are looking for, but they're not going to move even a centimeter the government's will and this president's will to seek peace," Santos said.

Of the 10 injured in Thursday's attack only one remains hospitalized and is in intensive care on a respirator.

Authorities have offered $40,000 for information leading to the arrest of the perpetrators.

Gen Humberto Guatibonza, the head of Bogota's police, urged the city's 10 million residents to remain vigilant. He said there had been a number of false alarms reported in the past hours but that authorities have no indication another attack on the capital is being planned.

In the aftermath of the blasts, speculation had been rife that the attacks were orchestrated by the FARC. The group in May suspended a unilateral cease-fire and has been stepping up attacks across the country.

With apprehension running high, camouflaged combat troops carrying assault weapons patrolled several streets downtown Friday, randomly inspecting backpacks and asking pedestrians for their IDs.