One person was shot dead Tuesday and another four were wounded in a shootout between rival factions of Argentina's UOCRA construction union, doctors said.
The clash took place at dawn by a construction site in Villa Fiorito, a town in the Buenos Aires metropolitan area, and began with an argument over the assignment of jobs, police said.
Adolfo Avalos, 39, was shot in the chest and later died at the UPA clinic in nearby Lanus.
Of the four who were wounded, the one hurt worst was taken to another hospital with a bullet wound in the pelvis and is being kept under observation.
Avalos was "shot from an SUV," whose four occupants were arrested shortly afterwards, union delegate Jorge Santillan told reporters.
Both the shooters and the victims were UOCRA members, but the violence originated with followers of a faction led by Walter Leguizamon, the delegate said.
Leguizamon was arrested previously for a similar act of aggression in the greater Buenos Aires town of Florencio Varela.
Tension between the two union factions has grown in recent weeks.
Last Thursday, a grenade exploded in the home of Humberto Monteros, secretary general of the UOCRA of Bahia Blanca, in the southern part of Buenos Aires province.
Armed showdowns between factions of the same union or between different union organizations are common in Argentina, where in 2010 a young leftist militant was slain during a demonstration of railroad workers. EFE