ROME (Reuters) - Italian medical charity Emergency said on Friday that foreign troops, especially the British military, may have been behind the arrest of three Italian aid workers in Afghanistan's Helmand province.

An Italian doctor, nurse and logistics officer from the Milan-based charity were arrested on April 10 with six Afghans and accused of plotting to kill the governor of the southerly province. Rome has complained to Kabul about their treatment.

They were taken from a hospital run by Emergency in Lashkar Gah, capital of the violent province which is the scene of a major assault by U.S. and British forces against the Taliban.

ADVERTISEMENT

Provincial authorities said explosive suicide vests, hand grenades and pistols were found at the charity's hospital.

Britain's Defence Ministry said international forces were not involved in the arrests, but that British troops "deployed to the hospital ... at the request of the provincial governor's office" to secure the location after the arrests were made.

Gino Strada, leader and founder of Emergency, said: "There is a very serious chance countries in the coalition were involved, at least at the level of taking the decision".

"How does the English government dare to send armed soldiers into a hospital run by an Italian NGO? What would have happened if Italian soldiers had burst into a hospital run by an English NGO?" Strada asked at a news conference in Rome.

Emergency plans a rally in Rome on Saturday for the release of the nine who include Italians Marco Garatti, Matteo Dell'Aira and Matteo Pagani. Strada said they were "completely innocent" and 340,000 people have signed a petition for their release.

The foreign ministry in Rome said an Italian official had visited the three in jail in Kabul and they were in good health.

Emergency, which has worked in Afghanistan since 1999 including under Taliban rule, treats anyone at the Lashkar Gah clinic, regardless of which side they may have been fighting on.

ADVERTISEMENT

Emergency cannot explain the presence of arms but says it was possible that "one of the (Afghan) guards was bribed or threatened" to hide the weapons and explosives.

Strada said it could be part of an attempt to get rid of "independent observers" like his charity in Helmand ahead of a big new push against the Taliban.

(Additional reporting by Avril Ormsby in London; Writing by Stephen Brown; Editing by Dominic Evans)