The Bahraini government, meanwhile, reported progress toward starting a dialogue with the opposition after thousands of protesters took to the streets last week to demand an elected government in the kingdom.

Hassan Mushaimaa, the London-based leader of the Haq movement, had said on his Facebook page that he would fly home last Tuesday to see whether Bahrain's leadership was serious about dialogue with its opponents or would arrest him.

A Lebanese official said authorities had blocked Mushaimaa from boarding a flight to Manama because his name was on an international arrest warrant. A Lebanese judicial source said Mushaimaa's passport had been seized, but he was not in custody.

"The Bahraini government has distributed his name to borders in the Arab world," Abbas Al-Amran, a friend of Mushaimaa, told Reuters. "He will not let himself be arrested. He wants to take a plane and come to Bahrain as an ordinary citizen."

Mushaimaa is among 25 people charged last year over an alleged coup plot and was being tried in absentia. But the government freed the other defendants on Tuesday as one of several gestures to try to defuse anti-government protests that at their height drew tens of thousands.

A statement by King Hamad bin Isa on Monday hinted the trial would be shelved, which would let Mushaimaa return unhindered. Lebanese authorities were checking with Bahraini authorities on whether to let him fly to Manama, the Lebanese official said.

Crown Prince Sheikh Salman bin Hamad has offered dialogue with the opposition. "Talks with representatives of Bahrain society and the crown prince continue and positive progress is being made towards the commencement of the national dialogue," a government statement said.

The opposition Al-Wefaq party, however, said there had been "no progress at all". Former Wefaq lawmaker Ibrahim Mattar said his party wanted a clear commitment to a constitutional monarchy before coming to the table.