* Main Shi'ite opposition group not joining protests
* Bahrain has banned protests in Manama, toughened laws
* "Tamarrod" says it wants free and democratic Bahrain (Adds U.S. embassy closure)
MANAMA, Aug 14 (Reuters) - Bahrain has tightened security around some restive Shi'ite Muslim villages to try to thwart anti-government protests planned for Wednesday that have prompted the United States to temporarily close its embassy.
Activists said on social media they would try to force the Sunni Muslim ruling family to allow more democracy in the country of 1.25 million, taking inspiration from protests in Egypt that led to the removal of Islamist President Mohamed Mursi. They called on people to meet near the U.S. embassy.
But unlike in Egypt, where protesters were backed by the military, Bahrain's security forces remain loyal to a government that on Monday vowed to "forcefully confront" demonstrators and prosecute those responsible for "incitement".
The small Gulf Arab state and Western ally that hosts the U.S. Fifth Fleet has been buffeted by bouts of unrest since February 2011 when an uprising led by members of the Shi'ite majority demanded the al-Khalifa dynasty give up power.
The authorities crushed the revolt but protests and clashes have persisted despite talks between government and opposition, leaving Bahrain on the front line of a fight for regional influence between Shi'ite Iran and Sunni Saudi Arabia.
Wednesday's protest prompted the government to pass tough new laws banning demonstrations in the capital Manama.
Bahrain's largest opposition group, the Islamist al Wefaq Society, said it was not planning to join officially but it supported the right to peaceful demonstrations.
"From what I have been hearing around, I know that it is going to be a peaceful movement but having said that I also expect clashes between the government forces and the protesters, because they are against all protests and demonstrations," the Wefaq leader, Sheikh Ali Salman, told Reuters.
Wefaq said in a report on its website late on Tuesday that security forces had ringed some areas with barbed wire and blocked some streets with concrete barriers.
A Reuters witness said he saw police reinforcements, including some armoured vehicles, being deployed late on Tuesday outside mainly Shi'ite villages such as Sanabis, Sitra and Budaya where protests have previously taken place.
The new push for a "free and democratic Bahrain" is being driven by "Tamarrod" (Rebellion), a loose association of opposition activists who came together in early July, according to social media quoting the group.
Complaining of discrimination against majority Shi'ites in areas such employment and public services, the opposition is demanding a constitutional monarchy with a government chosen from within a democratically elected parliament.
The government denies any discrimination.
The U.S. embassy advised Americans to avoid non-essential travel inside the country and said it would close on Wednesday.
"I don't see where the problem is, why we are not allowed to ask for our demands and needs in peaceful demonstrations," a 24-year-old secretary, who asked not to be named, said.
But a 34-year-old banker, who also asked for anonymity, said such protests were intimidating.
"The anti-government societies tried to scare us on February 14 of this year ... but thanks to the forces they were not able to do anything," he said, referring to an earlier call for protests to mark the second anniversary of the 2011 uprising. (Writing by Sami Aboudi; Editing by Angus McDowall and Elizabeth Piper)