By Jeremy McDermott
BBC News, Medellin
Army officers in Colombia have been accused of placing car bombs around the capital in the latest military scandal to hit the country.
Evidence suggests the military are contributing to the violence
The officers hoped to claim reward money from the government's informants programme for discovering the bombs.
President Alvaro Uribe made a televised address to the nation urging Colombians to keep faith in the security forces, amid a growing crisis in confidence.
He has made the strengthening of the military his government's cornerstone.
Such is the crisis in confidence in the military that President Uribe decided that he had to show his face to the nation and reassure Colombians that his military, backed by Washington, was not spinning out of control.
In the latest scandal, army officers are accused of placing car bombs around Bogota, including one that went off wounding more than a dozen soldiers and killing a civilian.
The motivation was to claim reward money from the government, which offers payments of up to $400,000 (£220,000) for information on the activities of Marxist rebels and drugs traffickers.
In another incident, 10 policemen were killed by the army in what was presented as a friendly fire tragedy.
However, evidence has shown that they were killed at point-blank range.
Several soldiers, including a colonel, have been arrested and accused of murdering the policemen on the orders of a notorious drug baron.
Mr Uribe insisted that these scandals are isolated incidents and that things are getting better.
But evidence now suggests that the military are contributing to the violence, not just fighting it.