MANAMA (Reuters) - Bahrain issued arrest warrants on Wednesday for 20 people accused of injuring policemen and civilians with homemade bombs during months of pro-democracy unrest in the island kingdom.
In another sign of a crackdown on dissent, well known activist Nabeel Rajab appeared in court charged with using the online messaging service Twitter to insult authorities, his lawyer said.
Bahrain has been in turmoil since protesters, mainly from the Gulf Arab state's Shi'ite Muslim majority, took to the streets calling for democratic reform in early 2011.
More than a year later, protests have continued to erupt and recently intensified, with daily clashes between police firing teargas and youths throwing petrol bombs.
The interior ministry said it had issued the names and photographs of 20 men, aged 18 to 38, wanted for preparing and detonating "terrorist explosions".
Police say 15 officers have been wounded by three blasts, the first in early April.
Bahrain's opposition Wefaq party says 81 people have died, some in custody, since the start of the uprising. The government rejects the figure, saying many of the dead had succumbed to pre-existing medical conditions.
Nabeel Rajab, founder of the Bahrain Centre for Human Rights, was charged on Wednesday with "insulting an official authority" on Twitter, his lawyer told Reuters.
The case focused on four online messages that suggested the interior ministry had not carried out proper investigations into civilian deaths, lawyer Mohammed al-Jishi said.
The judge adjourned the case for a week and extended Rajab's detention, Jishi added.
Rajab has already been accused of organizing illegal protests, charges that could seen him jailed for up to two years said Jishi.
Police fired teargas to disperse several dozen protesters who gathered in the district of Daih on the edge of the capital Manama on Wednesday, demanding the release of Rajab and women protesters including Zainab al-Khawaja, daughter of an opposition leader on hunger strike.
The opposition says the ruling Al Khalifa family, which has rejected demands for an elected government in Bahrain, an important U.S. ally against Iran, does not want to cede powers.
(Reporting by Hamad Mohammed in Manama and Andrew Hammond in Dubai; Writing by Andrew Hammond; Editing by Andrew Heavens)