A group of Congolese soldiers went on trial Tuesday over a horrific blast at a munitions dump in Brazzaville last year that left almost 300 people dead.

The 23 soldiers, charged with arson and harming state security over the March 2012 disaster, appeared in a packed courtroom in the Congolese capital.

Security was high, with special police deployed outside the court for the hearing.

More than 2,300 people were injured in the blasts at the Mpila munitions dump that flattened hundreds of houses in the capital, leaving some 17,000 homeless.

The investigation led to the arrest of 26 people including the deputy chief of the national security council. Three arrested civilians were later released.

"We have a good case. We are going to the trial very confident. If justice can be rendered in the name of the Congolese people, that would be a good thing," defence lawyer Amedee Nganga, told AFP.

Colonel Marcel Tsourou, former deputy secretary general to the National Security Council, is among the defendants.

His wife Charlotte Tsourou charged that his indictment was "political and guided from above."

The trial continues Wednesday.

Last Thursday several dozen people who were left homeless by the blast and living in tattered tents staged a protest demanding proper housing as the rainy season approaches.

Police dispersed them with tear gas and made several arrests.