BANGKOK - Thailand's army chief Apirat Kongsompong, in unprecedented remarks on Friday (Oct 11), said the kingdom is being threatened by a conspiracy to create a Hong Kong-style uprising.

In a public lecture at army headquarters in Bangkok, the first of its kind since he assumed command of the armed forces last October, General Apirat vowed to suppress any attempt to undermine national security.

"Those using social media are manipulating the youth to go out on the streets like in Hong Kong," he said in the one-and-a-half-hour-long speech to hundreds of army officers, members of the press and school and university students.

During the presentation, pictures of Joshua Wong, a prominent Hong Kong pro-democracy activist and politician, were shown on the big screen to warn Thai youth not to follow Hong Kong's example. The city has been gripped by a series of anti-government protests, many of which have turned violent since June.

The 59-year-old general on Friday noted that the Hong Kong activist met a Thai politician recently.

Mr Wong uploaded a photo on Facebook on Oct 5, 2019, showing himself with Mr Thanathorn Juangroongruangkit, whom he had met at The Economist magazine's Open Future Festival in Hong Kong.

Mr Thanathorn, who is the leader of the progressive Future Forward Party, is facing multiple lawsuits at home for criticising the military regime in power from 2014 to early this year.

He is also among 12 people, including opposition politicians and academics, who were charged last week with sedition for raising the possibility of amending the military-drafted Constitution, which was approved in a nationwide referendum in 2016, at a public forum in southern Thailand.

The region bordering Malaysia has been wracked by tensions for decades, with more than 7,000 people reported killed since 2004 following an upsurge in a Muslim separatist insurgency.

"I'm not saying that the Constitution can't be amended. But when it comes to Article 1, it's about national security. It's about our ancestors' sacrifice. I can't let it happen," Gen Apirat said with the text of the Article which says "Thailand is a unified kingdom and cannot be separated" displayed on the screen.

"These academics are smart. They know that if Article 1 is amended, other clauses in the Constitution will be affected," the general added.

A hardline royalist and nationalist, Gen Apirat on Friday described how the monarchy and the army were the main institutions protecting Thailand's sovereignty, going through historical events when the kingdom lost some of its territory through wars and during colonial times. But he emphasised that Thailand was the only country in South-east Asia that was never colonised.

The general spoke about a conspiracy to change the Thai government , saying the country was fighting a hybrid warfare involving cyber attacks, information propaganda and irregular forces involving terrorists and those working against the authorities.

"This is a serious issue in many countries. But it's particularly worrisome in Thailand. There are old communist groups looking to overthrow the monarchy," Gen Apirat said.

He singled out those who had joined or sympathised with the communist movement in the 1970s, saying they had now become academics "teaching students wrong things."

"I'm not involved in politics. The army has stepped back now that there's an elected government. But this is about national security. I will never let anyone separate the country," he said.

Thailand has seen 12 successful military coups since it transitioned from absolute monarchy to constitutional monarchy in 1932.

Mr Thanathorn responded to the army chief's comments on Facebook, acknowledging that he met Mr Wong briefly on Oct 5 while speaking at a forum in Hong Kong and said that he had no involvement in the current situation in the territory.

"Some people including the army chief are trying to link me to the unrest in Hong Kong to create hatred in Thai society," he said.