The Chinese embassy in Bangkok has condemned Thai politicians for showing support to Hong Kong activists amid mass anti-Beijing protests, saying that such a move could harm the relationship between the two countries.

The criticism was echoed by Thailand’s army chief, who on Friday spoke of “hidden agendas” in meetings between opposition activists.

The embassy statement, posted on its official Facebook page late on Thursday, came days after Hong Kong pro-democracy activist Joshua Wong posted a picture on social media with prominent Thai opposition figure Thanathorn Juangroongruangkit.

“Some Thai politicians have contacted the group that wants to separate Hong Kong from China, showing gestures of support,” the embassy said in a Thai-language statement without naming the individual politicians.

“This is wrong and irresponsible. China hopes that relevant people will understand the truth about problems in Hong Kong, act carefully and do useful things for the friendship between China and Thailand.”

Wong and Thanathorn met on October 5 at the Open Future Festival in Hong Kong, attending as speakers at the annual event.

“Under the hard-line authoritarian suppression, we stand in solidarity,” Wong wrote in a tweet that showed a picture of him standing next to the Thai politician.

In the same post, Wong was also shown posing with Australian Liberty Party member of parliament, Tim Wilson, who has expressed his support of the pro-democracy movement, by marching in Hong Kong.

Thanathorn’s Future Forward Party declined to comment when contacted by Reuters news agency on Friday.

In a statement on social media, Thanathorn acknowledged that he met Wong during a public event, in which he was among the invited guests.

“That was the first and only time that Johuan Wong and I met. I have never contributed to any political group in Hong Kong, and there is no intention for me to do so in the future. My mission of my party and myself is to create democracy and progress in the Thai society.”

Thai army chief General Apirat Kongsompong indirectly criticised Thanathorn’s meeting with Wong on Friday during a press briefing in which he accused opposition politicians of inappropriate behaviour.

“Wong came to Thailand countless of times. To meet whom? The meetings had hidden agendas. Were [are] they conspiring, cooking up something together?” Apirat said.

“And with the incidents in Hong Kong, someone went, to give moral support, to give encouragement,” Apirat added, showing the picture of Thanathorn and Wong that was posted on social media, though Thanathorn’s body was blacked out.

Thailand was run by a military government for five years after then-army chief General Prayuth Chan-ocha overthrew an elected government.

Elections held in July were won by Prayuth’s pro-army party in a vote that opposition parties said was organised to ensure the continuation of military control of politics.

The Thai Foreign Ministry declined to comment on the Chinese embassy’s statement but referred to a statement in September stating that Thailand regards the situation in Hong Kong as China‘s internal affairs.