Two explosions rocked the Colombian capital Bogota on Thursday leaving at least five people hurt, according to firefighters, who said the cause was not immediately known.

The blasts hit in the financial heart of Bogota -- where the five were injured -- and then at an industrial zone in the capital, firefighters said on Twitter.

There were no casualties in the second explosion, local media said.

The blast in the financial district hit at around 3:45 pm (2045 GMT), smashing windows, an AFP reporter said.

"It made a very loud noise," said Argemiro Sanchez, 52, a street vendor.

The injured were rushed to a hospital and police were investigating what caused the explosions.