Colombian police officers and firefighters check the site of an explosion in the financial heart of Bogota.

Story highlights

NEW: Colombia's President blames National Liberation Army for the twin bombings

At least 8 people were injured in two blasts, Bogota's health secretary says

The explosions occurred near offices for the Porvenir pension fund management company

CNN  — 

Two explosions rocked Colombia’s capital on Thursday, injuring at least eight people.

The blasts took place outside the offices of the Porvenir pension fund management company, according to CNN affiliate Cablenoticias.

Images showed shattered glass on the ground and emergency personnel at the scenes.

On Friday, Colombian President Juan Manuel Santos blamed the National Liberation Army, a leftist guerrilla movement known as ELN.

“The information that we have now indicates the perpetrators are the ELN guerillas and there is evidence to indicate this,” Santos said in an address aired on Colombian state-run television.

Security measures are being reinforced in Bogota because of the attacks, he added.

ELN is the second-largest rebel group in Colombia, behind FARC.

A day earlier, Colombian Defense Minister Luis Carlos Villegas described the explosions as “terrorist acts” and said the government was offering a reward of up to 100 million pesos (about $38,000) for information about who was responsible for them.

The first blast, which occurred in the financial district, injured seven people. The second blast, in an industrial area of the city, left another person wounded, Bogota Health Secretary Mauricio Bustamante told reporters.

None of the injuries was life threatening, he said.

CNN’s Richard Beltran, Michael Roa, Pierre Meilhan and Catherine E. Shoichet contributed to this report.