Prosecutors in Venezuela say a soldier opened fire at an army base in the capital, Caracas, killing two officers and wounding six other soldiers.
The soldier reportedly had an argument with a captain during the change of guard at Fort Tiuna.
He then shot the captain in the head with an AK-103 assault rifle, before shooting dead a lieutenant, the attorney general's office says.
Six other people were also injured.
The soldier, who has been named by the attorney general's office as Jeffersson Jose Trujillo Vasquez, escaped in a car which was later found abandoned in Caracas.
Police are still searching for him.
Last week, the fort was the scene of another shooting when a player at the women's baseball world cup was hit by what officials say was a stray bullet. The cup was moved to the city of Maracay, west of Caracas.
The Venezuelan capital is regularly listed as one of the most dangerous in Latin America.
But Fort Tiuna military base is considered to be one of the safest places in Caracas.
President Hugo Chavez has been known to stay the night at the officers' mess, and a residence belonging to the vice-president is on the military compound.
High-ranking foreign delegations are also often hosted there.