BANGKOK (Reuters) - Hundreds gathered at a Bangkok university on Saturday to deliver an ultimatum to Thailand’s military government, the latest in a series of anti-government demonstrations that began earlier this year.

People protest against Thailand's Prime Minister Prayuth Chan-ocha in Bangkok, Thailand May 5, 2018. REUTERS/Soe Zeya Tun

Thailand has been under military rule since a May 2014 coup which the army said was necessary to restore order after months of pro and anti-government protests.

The military had vowed to bring stability and reform what it said was Thailand’s corrupt political system.

Four years on, critics say the country remains deeply divided and that the junta has failed to deliver on some of its promises.

And international organizations including the United Nations say freedom of assembly and speech have suffered huge setbacks under military rule.

The military has defended its hardline tactics saying it needs to maintain national security before a general election.

The government, led by former army chief Prayuth Chan-ocha, has repeatedly delayed elections with the latest date now set for February 2019.

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On Saturday, more than 500 demonstrators gathered at Thammasat University and gave the junta, known formally as the National Council for Peace and Order, until May 22 to meet their three demands.

The protesters are calling for an election to take place by November, said Rangsiman Rome, one of the group’s leaders. They are also asking for the junta to step down and for soldiers to return to their barracks.

Rangsiman said they would march to Government House on May 22, the fourth anniversary of the 2014 coup, to put pressure on Prayuth if their demands were not met by then. He did not say what specific action was planned after May 22.

Protest leaders gave speeches against a red backdrop with graphics showing a black outline of the city’s Democracy Monument and a large microphone.

Police said around 600 officers were deployed at the protest.

“They’re here to maintain security … and to look out for weapons,” said Chakrit Chosoomuang, commander of Chanasongkram police station.

“There are hundreds of protesters here but we have yet to detect anything suspicious,” he said.

Reuters was unable to reach a spokesman for the military government for comment.

Saturday’s protest is the latest in a wave of demonstrations that began in earnest in January.

On Wednesday, hundreds gathered outside the United Nations’ regional headquarters in Bangkok and two other locations to urge the government to end the “intimidation” of community activists by the authorities.