Bahrain says seizes explosives, fines protest chief DUBAI (Reuters) - Bahrain has seized large quantities of materials used to make explosives, the Gulf Arab state's public security chief said, as clashes between police and protesters persist more than a year after the start of a pro-democracy uprising. "The explosives were designed to cause severe injury, a high death toll, serious destruction to property and fear in the minds of the public," Tariq al-Hassan said in comments published by the government Information Affairs Authority. He said more than five tons of materials had been seized at several sites described as "terrorist dens" by the state news agency late on Wednesday. Newspapers published pictures of an array of chemicals, wires, plastic pipes and three wanted men. "This is significant as it indicates a new level of terrorist activity in Bahrain," Hassan said. Bahrain, where the U.S. Fifth Fleet is based, has been in turmoil since pro-democracy protests by majority Shi'ite Muslims began in February 2011 after popular revolts overthrew long-serving heads of state in Egypt and Tunisia. The Manama government, dominated for generations by the Sunni Muslim Al Khalifa family, accuses the opposition of having a Shi'ite sectarian agenda and links to regional Shi'ite giant Iran. The opposition denies this, saying such allegations amount to a pretext for avoiding democratic reforms. After a pause following a military crackdown in March 2011 aided by Saudi troops, violence has resurged with some attacks on police using homemade explosives. Protesters have thrown petrol bombs and iron bars at police in response to what they say is stepped up use of birdshot by security forces. Thirty-five people died during the uprising and a period of martial law last year, but the opposition says more have died in violence since. A protester was found dead on a rooftop in April, his body riddled with birdshot, a night after he was involved in fighting with police. There have been some talks between the government and the le3ading Shi'ite opposition party Wefaq this year but no solution to the conflict has emerged. On Wednesday, a judge released protest leader Nabeel Rajab after three weeks in detention over a Twitter post that criticized the prime minister, seen as a leading government hawk who has occupied the post for 41 years. Rajab's tweet said financial incentives had motivated residents of a district of the island to come onto the streets in support of the premier, according to his lawyer Mohammed Al-Jishi, who said a court would hear the case next month. Rajab, head of the Bahrain Centre for Human Rights, was fined 300 Bahraini dinars ($800) on Thursday for another tweet that suggested the Interior Ministry was responsible for weapons used by Sunni vigilantes to attack Shi'ites. But the court lifted a travel ban on Rajab, who still faces three additional charges of organizing illegal protests. He was also held in May for three weeks pending investigations into charges of illegal gathering and insulting the Interior Ministry. Rajab declared that the cases were meant to stop him organizing unlicensed protests in the capital. "Normally in such cases you get fined, but I've been in jail for 45 days without any verdict in these cases yet," he said on Wednesday after his release. Writing by Andrew Hammond; Editing by Mark Heinrich