Bahrain is facing international condemnation for its violent suppression of a Shiite uprising against the minority Sunni leadership.
Human-rights groups claim authorities are arresting hospital staff and some patients suspected of taking part in protests.
Physicians for Human Rights in April said it had forensic evidence Bahraini security forces attacked medical staff and patients with bullets and chemical agents.
At least 47 healthcare workers were charged with various crimes since protests broke out more than four weeks ago, and as many as 150 are under investigation by Bahraini authorities.
One medic told Arabic broadcaster al-Jazeera they were coerced into making confessions during interrogations.
"We were blindfolded for about 10 hours. Only at the time when [we] were videotaped did they take the blindfolds off," one medic said. "When we started to talk, if they didn't like the things that we were saying they stopped us and told us again that we should say this, this and this."
Bahrain denies the allegations.
In March U.N. High Commissioner for Human Rights Navi Pillay described the March 16 seizure by security forces of a hospital in Bahrain as "shocking and illegal conduct."