Bogota: A controversial deal allowing the United States to use seven bases in Colombia has triggered a storm of questions in the South American nation over an immunity clause for US personnel.

The government in Bogota has defended the agreement to protect US soldiers, pilots and sailors from prosecution for any wrongdoing, saying “immunity does not mean impunity.”

But critics fear the contrary.

“Immunity for United States soldiers is not in any way justified,” the former head of Colombia’s constitutional court, Jose Gregorio Hernandez, told AFP.

“It violates the principle of equality vis-a-vis our own soldiers. This immunity could become impunity because… a slow and likely unsuccessful diplomatic process would be required (before justice could be applied),” he said.

The issue of the bases has also become contentious for Colombia’s neighbors, notably leftwing anti-US nations Venezuela and Ecuador that fear they could be used to launch invasions.

Brazil, Argentina, Chile and Bolivia have all also expressed concern about the facilities, fearing a resurgence of US military might and meddling in South America after a rollback in the 1990s.

The US government and military have insisted that the bases — three airbases, two army facilities and two navy bases — simply extend US involvement in combating drug trafficking from Colombia. They say the number of personnel will be limited to 800.

Under a “Plan Colombia” launched in 1999, the United States has given Colombia more than 5.5 billion dollars in aid, much of it spent on military hardware and training to fight cocaine-running gangs and leftwing rebels.

While an agreement in principle has been struck on the bases, a spokesman for the US State Department, Ian Kelly, told reporters on Tuesday that a final signature would likely come in “a few more weeks.”

Inside Colombia, the granting of immunity in the deal has raised hackles.

Some recall with anger a 2007 case in which a Colombian woman claimed her 12-year-old daughter had been raped by a US army sergeant and a US civilian contractor attached to the Plan Colombia program.

Others discount assertions by the Colombian and US governments that any US personnel accused of crimes will be fairly judged by US courts.

“No-one will believe, given the current international situation, that ‘Gringo courts’ or US jurisdiction will exist,” an international analyst in Colombia, Juan Carlos Eastman, told AFP.

“Immunity means impunity in practice,” he said.

A former defense minister, Rafael Samudio, questioned the lack of information on the issue and noted that the United States consistently sought to keep its military personnel protected from non-US prosecution.

“The United States by principle does not allow a soldier to be judged in another country or hand one over. That’s why it has not signed on to the ICC (International Criminal Court),” he said.

“The United States has a completely different concept of its military than us,” he said.

The unease generated by the immunity for the US personnel prompted a response from Colombia’s foreign minister Jaime Bermudez before he flew to Washington for further discussions on the bases.

There would be no US courts martial or US jurisdiction in Colombia under the terms of the deal, he said on Sunday.

Colombian law enforcement officers could participate in the investigation of any transgression.

He insisted that there was “a possibility” of asking for immunity to be lifted against US personnel, and that in any case “the United States has promised to pay any indemnities” arising from a criminal act.

Importantly, he said, US civilian contractors would not be covered by the immunity clause.