By Daniel Wallis and Diego Ore

CARACAS (Reuters) - A Venezuela National Guard captain died on Monday after being shot in the head during a demonstration, the military said, the 29th fatality in six weeks of clashes between protesters and security forces.

General Padrino Lopez, head of the armed forces' strategic operational command, said the captain was shot late on Sunday at a street barricade set up by demonstrators in the central city of Maracay, in Aragua state.

"He was another victim of terrorist violence," Lopez said on Twitter, calling for an end to the confrontations.

"Our armed forces don't repress peaceful protests, they protect them ... Much more Venezuelan blood would have been shed if it were not for the responsible actions of our National Guard."

Since early February, students and hardline opposition leaders have been calling supporters onto the streets to protest against President Nicolas Maduro and his socialist government.

The demonstrators are demanding political change and an end to high inflation, shortages of basic foods and one of the worst rates of violent crime in the world.

The protests, however, show no signs of toppling Maduro, a 51-year-old former bus driver who narrowly won an election in April 2013 to replace his late friend and mentor, Hugo Chavez.

The armed forces seem to be firmly behind Maduro, and the protesters are far fewer than those who took to the streets a decade ago to oust Chavez, albeit briefly. Opposition leaders, meanwhile, are deeply divided over the current confrontations.

During the daytime, thousands of opposition supporters have marched peacefully. Then a masked hard core has been emerging in the evenings, especially in wealthier eastern Caracas, to fight running battles with riot police and the National Guard.

'CHINESE MERCENARY' CAPTURED

Tareck El Aissami, governor of Aragua state and a member of the ruling Socialist Party, said authorities arrested a "Chinese mercenary" near where the National Guard captain was killed.

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"This terrorist was captured carrying a firearm - a Glock pistol, and we found an arsenal in his home," Aissami said, showing video of hundreds of rounds of different calibers.

"We also seized a revolver, advanced telecoms systems, two-way radios, military uniforms, helmets, balaclavas and tear gas canisters," the governor said, adding the haul was "irrefutable proof" the opposition had violent plans.

Aissami gave the man's Venezuelan identity card number, but did not elaborate on the raid or where the man was from originally. The government has often talked about alleged assassination plans, rarely with many details.

Supporters of both political camps, and several members of the security forces, have been killed. Hundreds of people have been injured, and more than 1,500 have been arrested.

About 100 people remain behind bars, including 21 security officials accused of crimes ranging from brutality to homicide.

In the western border state of Tachira, which has been hardest hit by the violence, residents rebuilt some barricades overnight on streets that the authorities had cleared.

In Puerto Ordaz, in the south of the country, Reuters witnesses said riot police clashed with hundreds of students.

The opposition Popular Will party said it was planning a march in Caracas on Tuesday to mark a month since its hardline leader, Leopoldo Lopez, handed himself in to face charges of fomenting unrest after helping kick off the demonstrations.

In the capital on Sunday, National Guard troops fired tear gas and water cannons to clear anti-government demonstrators from Plaza Altamira, a square in the wealthy east of the capital that became the wreckage-strewn site of daily violent clashes.

"For a month this was the object of terrorism and vandalism," Information Minister Delcy Rodriguez told state TV at the square, which features an obelisk, a fountain and a view of Mount Avila, which towers above the city.

"Today it is a territory of peace."

National Guard troops posted around the plaza said they had seized home-made shields, materials for Molotov cocktails, and medicines used by the protesters to counteract tear gas.

As they searched the bags of passers-by, they told a Reuters reporter they had been deployed to the area for 15 days.

Cenaida Pavon, a 40-year-old secretary walking through the square, said she supported the demonstrators' right to protest peacefully but not the destruction of property.

"They hate what President Chavez left behind," she said, adding that the nearby school her eight-year-old son went to had been closed since the start of the demonstrations.

"That's terrorism, not protest," Pavon said.

(Additional reporting by Javier Faria in San Cristobal and German Dam in Puerto Ordaz; Editing by James Dalgleish)