Bahrain Mirror (AFP): Bahrain's prosecutor said Sunday he would not press new charges against Sheikh Ali Salman, the jailed leader of the main Shiite opposition bloc, in connection with messages posted on Twitter.

The prosecutor general summoned Salman from prison, where he is serving a sentence for inciting disobedience, for questioning about "violations" posted on his Twitter account, the official BNA news agency reported.

It later said that Salman denied any wrongdoing and that the prosecutor decided not to press charges and ordered him returned to prison to serve the rest of his sentence.

The prosecution also ordered an investigation into who was behind the tweets which, according to BNA, "incited" against the government and called for demonstrations.

Salman's Al-Wefaq bloc earlier denounced the summoning of its chief by the prosecution, saying it "violates the Bahraini constitution and national law, as well as international covenants related to freedom of opinion and expression".

The opposition chief was sentenced on June 16 to four years in jail after being convicted of inciting disobedience and hatred.

An appeals court is reviewing that conviction, but the prosecution is demanding the annulment of his acquittal on the more serious charge of plotting to overthrow the regime and seeking a tougher sentence.

A ruling on the appeal is expected on March 30.

Al-Wefaq renewed earlier calls for its leader to be released "immediately".

The group once held the most seats in parliament, but its 18 MPs walked out in 2011 in protest at violence against demonstrators during pro-democracy rallies.

Bahrain's Sunni authorities crushed Shiite-led protests a month after they erupted on February 14, 2011.

The gap has since been growing between the Sunni authorities and their mainly Shiite opponents.

Tiny but strategic Shiite-majority but Sunni-ruled Bahrain is across the Gulf from Shiite Iran and home to the US Fifth Fleet.

Last October 31, construction work also began in Bahrain on Britain's first permanent military base in the Middle East since 1971