* Protesters model movement on Egypt and Tunisia revolts
* Five killed in eastern town of Al Bayda -local source
* Phones down, access barred to area of clashes
(Edits, updates with Amnesty International statement)
TRIPOLI, Feb 17 (Reuters) - Deadly clashes broke out in several towns in Libya on Thursday after the opposition called for protests against leader Muammar Gaddafi in a rare show of defiance inspired by uprisings in other Arab states.
Tight controls on media and communications in Libya made it difficult to assess the extent of the violence there. Unrest has spread across North Africa and the Middle East since the fall of the leaders of Tunisia and Egypt. A resident in the eastern city of Benghazi said at least five people had been killed in nearby towns. With phone lines out of order and access barred for journalists, it was impossible to establish an exact death toll.
In the capital of the oil-exporting country there was no sign of unrest, a Reuters reporter said, apart from a group of pro-Gaddafi demonstrators in the city's Green Square chanting "We are defending Gaddafi!" and waving his portrait.
Opponents of Gaddafi, Africa's longest-serving ruler after more than 40 years in power, had used social media to call for protests on Thursday to try to emulate the revolts which unseated rulers in neighbouring Tunisia and Egypt.
The source in Benghazi, who said he had been in contact with people in the nearby town of Al Bayda, said two young men had been killed there on Wednesday and three more had died in clashes after their burial.
The same source said there were reports of several deaths in Ajdabiya, about 160 km (100 miles) west of Benghazi.
Gaddafi's opponents say they want political freedoms, respect for human rights and an end to corruption. Gaddafi says Libyans enjoy true democracy.
The worst clashes appeared to have taken place in the eastern Cyrenaica region centred on Benghazi, where support for Gaddafi has historically been weaker than in other parts of the country.
Earlier, a resident in Al Bayda told Reuters by telephone: "The situation is still complicated ... The young people do not want to listen to what the elders say."
Phone connections to the town, which is 200 km from Benghazi, were not working on Thursday evening and officials were barring journalists from flying to Benghazi from Tripoli.
Libya's Quryna newspaper reported that the regional security chief had been removed from his post over the deaths of protesters in Al Bayda.
Rights watchdog Amnesty International said security forces opened fire on protesters in Al Bayda, killing a man it named as Nacer Miftah Gout'ani.
"The Libyan authorities tried to smother this protest before it even got off the ground but that, clearly, did not work. Now they are resorting to brutal means to punish and deter the protestors," the group said in a statement.
A group calling itself the Citizens' Forces of Eastern Libya issued a declaration urging an end to the clashes, saying the government would use violence as a pretext to ignore demands for freedom and justice.
The declaration, obtained by Reuters, proposed a truce until March 2 to "give the regime an opportunity to show its commitment towards transparency and accountability". A source close to the group said it included influential members of Libya's ruling establishment.
Snatches of information about the protests were trickling out from parts of the country on an Arabic-language page used by opposition activists on Facebook, the social networking site.
One post said protesters in Ar Rajban near the border with Algeria set fire to a local government headquarters. In Zenten, south-west of Tripoli, protesters shouted "we will win or die," said another post, which had a photograph of a building on fire.
In the capital, traffic was moving as normal, banks and shops were open and there was no increased security presence.
Political analysts say the government's oil wealth gives it the capability to smooth over social problems and reduce the risk of an Egypt-style revolt.
"We have problems," Mustafa Fetouri, a Tripoli-based political analyst and university professor, told Reuters. "This is a society that is still behind in many ways, there are certain legitimate problems that have to be sorted out."
However, he said: "I do not really see it (unrest) spreading ... Gaddafi remains well respected."
On the eve of Thursday's protests, SMS messages were sent to mobile phone subscribers throwing down a challenge to anti-Gaddafi protesters. "From the youth of Libya .... Come and face us in any square or street in Libya," it said. (Additional reporting by Hamid Ould Ahmed and Lamine Chikhi in Algiers; writing by Christian Lowe; editing by )