Manama - About 400 people have been put on trial in Bahrain for their roles in weeks of protests that rocked the Gulf island kingdom this year, a leading opposition group said on Thursday, but the government disputed the figure.

Wefaq, which represents Bahrain's Shi'a majority, said up to 50 people had already been sentenced, with penalties ranging from a short prison term to execution.

The Sunni ruling al-Khalifa family quashed the Shi'a-led rallies in March, summoning support troops from neighbouring Sunni-ruled countries and imposing emergency law, which was lifted last week.

Bahrain, host of the US Navy's Fifth Fleet, said the democracy protests had a sectarian agenda and were backed by Shi'a power Iran, just across Gulf waters. The opposition deny this.

“I think around 400 have been called to trial, but it's hard to know because every other day we hear of more people being asked to present themselves to court,” said one Wefaq official.

“It will be hard to know how many were put on trial until after the calls stop.”

Bahrain's government called Wefaq's trial data exaggerated.

“It's much less than that,” said a government source who declined to be identified. He did not offer alternative figures.

Defendants have faced charges ranging from illegal assembly, falsifying news, defamation, incitement of hatred against Bahrain's rulers and the killing of a policeman.

Twenty-one activists face charges of attempting a coup in coordination with a foreign terrorist organisation - among them the prominent hardline Shi'a dissident leader Hassan Mushaima and Ebrahim Shareef, head of the leading secular party Waad.

Defendants and the relatives of detainees called to trial have told Reuters they are given very short notice of the trials, usually less than 24 hours before the hearing.

“Yesterday some families called me to complain they were given only 10 to 12 hours' notice about a trial for their relatives in jail. How does this give them time to get a lawyer and prepare?” said Nabeel Rajab, head of the Bahrain Centre for Human Rights. He also estimated trials to be in the hundreds.

Bahrain's military prosecutor-general, who is overseeing most of the proceedings, has said initial hearings in court are to establish whether defendants have a lawyer, and that attorneys can meet their clients before the next session.

Relatives of detained defendants dispute this, arguing lawyers do not get enough time to see jailed clients.

Some activists warned that the rising number of trials would fuel popular anger ahead of July 1 reconciliation talks set by King Hamad bin Isa al-Khalifa with the opposition.

Tensions continue to simmer in Shi'a communities, with small protests breaking out daily.

“People are shocked by the situation. They're being called for dialogue even while we keep getting these calls to go to court. It's hard to rationalise this phenomenon,” said one opposition figure, who declined to be named. - Reuters