Police refused to comment on the investigation, or to discuss possible motives or suspects.
All four victims frequented Plaza Altamira, the site of more than 120 days of protests against Chavez' government. The dead military men had also joined a call for popular resistance led by anti-Chavez Gen. Enrique Medina.
A 14-year-old girl who apparently witnessed at least one of the killings was hospitalized after being shot, but is talking, police said.
Raul Yepez, deputy director of the Caracas police homicide division, said the four victims had been fired upon with shotguns. It appeared that all of them went missing last week.
"We are conducting the investigation to try to answer these questions," he said.
Despite occasional violence in Venezuela's political standoff, there have been no confirmed selective killings of Chavez's allies or enemies. Still, street clashes have claimed at least seven lives and left scores injured since December.
The Venezuelan leader says his self-styled "revolution" for the poor is a peaceful one. His opponents, however, blame his aggressive class-warfare rhetoric for inspiring his supporters to take up arms.
Police said the victims were army soldier Darwin Arguello, marine infantry corporal Angel Salas and air force soldier Felix Pinto.
FORENSICS REPORT
A forensics report seen by Reuters indicated that a least of two of soldiers had been dead for about 72 hours. Their bodies were abandoned on the side of a multi-lane highway heading out of Caracas.
Yepez said at least one other victim was found on a farm on the outskirts of the capital.
The civilian victim, Zaida Perozo, had been wounded during a Dec. 6 shooting at Plaza Altamira, where she was protesting, said Carlos Bastidas, a lawyer for the dissident military officers.
At least one gunmen left three people dead and more than 20 injured in that attack which opposition leaders blamed on the government. Pinto was a material witness to the incident and had been considering testifying against the alleged shooter, Joao de Gouveia, said Bastides.
"It's very easy to put forward ideas or personal judgments ... but there is an element between this case and the case of Joao de Gouveia: that is one of the victims and a witness to Dec. 6 have died," Bastidas said.
Chavez is struggling to consolidate his power after surviving a coup last year. He has rebuffed calls by his opponents for early elections to cut short his term in office, which is set to end in 2007. [End]
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The civilian victim, Zaida Perozo, had been wounded during a Dec. 6 shooting at Plaza Altamira, where she was protesting, said Carlos Bastidas, a lawyer for the dissident military officers.
December 7, 2002 Opposition protests for referendum on Chavez drives Venezuela deeper into crisis*** CARACAS, Venezuela - Venezuela's opposition stepped up protests against President Hugo Chavez's government Saturday to demand his resignation after three people were killed and 28 others wounded at an opposition rally.
The opposition declared Saturday a national day of mourning as hundreds of people in black clothing gathered at Plaza Francia. More confusion reigned as protesters wrested handguns from two people in the crowd they called "infiltrators."
Opposition leaders blamed Chavez supporters for the fatal shootings during a protest Friday night at an eastern Caracas plaza, which threatened to ignite more violence in a 6-day-old general strike to unseat Chavez. Hundreds of people were listening to a speech Friday night at the Plaza Francia, the opposition's main rallying point, when several bursts of gunfire were heard.
People dived to the ground and huddled together to protect themselves. Bloodied people were hustled into ambulances and bystanders tried in vain to revive the dead.
"They came out of nowhere and started shooting like crazy," said Gabriela Barreto, 19, who suffered a gunshot wound to her abdomen.
Some opposition leaders were quick to blame the president for the attack. Chavez said he was appalled by the accusations.
Pedro Aristimuno, head of Caracas' health department, said the dead included a 17-year-old girl, a 70-year-old woman and a 44-year-old man. Leopoldo Lopez, mayor of the Caracas district where the plaza is located, said 28 people suffered bullet wounds.
Seven suspects were detained, including one Lopez said confessed to shooting at the crowd. It was unclear what role the other detainees - who included British citizen Frank Ignacio Pieret - were accused of playing. But Lopez said so many injuries "could not have been caused by just one person."
Police confiscated a handgun from taxi driver Joao De Goveia, 39, a Portuguese citizen who has lived in Venezuela for more than 20 years, Lopez said. He said Goveia admitted firing about 10 shots into the crowd.
A bloodied Goveia, shown on television as police shoved him into a sport utility vehicle, told journalists he had confessed. In a brief, confused statement, he said he targeted journalists allied with the opposition.
Goveia was taken to the Justice Ministry on Saturday for questioning.***
Hugo Chavez and 9/11, self-proclaimed leader if the new anti-Imperialist movement (pro-Commie), Venezuela's oil billions fund terrorism and protests.
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