Prime Minister Prayut Chan-o-cha has warned people to refrain from upsetting those who are still mourning the passing of His Majesty the King.
He said insensitive remarks and actions could provoke strong reactions that could lead to physical assaults, government spokesman Sansern Kaewkamnerd quoted Gen Prayut as saying Wednesday.
Gen Prayut also urged the public not to engage in vigilantism. He said it was up to authorities to take legal action against anyone who breaks the law.
The government warned against any attempts to get the monarchy embroiled into any conflict.
Lt Gen Sansern said that while some people may think differently from others, they should keep their opinions to themselves.
They should avoid speaking out or acting in a way that is insensitive to the feelings of the public who are grieving the loss of His Majesty the King. Otherwise, what they could get in turn is a barrage of dissatisfaction from others that could lead to physical harm, Lt Gen Sansern said.
"Don't try to provoke any conflict at the moment and don't get the monarchy involved in any conflict. Now is the time for all of us to unite," Lt Gen Sansern said.
The spokesman also said the prime minister was unhappy that some people were taking the law into their own hands and using violence against those who had allegedly insulted the monarchy.
While some people acted inappropriately towards the monarchy or posted "inappropriate" messages, it was also wrong for the public to use violence against them, Lt Gen Sansern said.
The move came after several incidents stirred up conflicts between the public and those who allegedly posted "inappropriate" messages concerning the monarchy in Phuket, Surat Thani and Phangnga in recent days.
The latest incident took place in Bangkok on Monday, when a a 55-year-old woman, who was said to have made insulting comments about the monarchy on a public bus, was slapped in the face by another woman. The victim reportedly suffered from a mental illness.
A ministry source said the countries include the US, France, Australia, Japan and New Zealand.
However, Gen Paiboon admitted it was difficult for foreign authorities to extradite those suspects, adding that Thai authorities had to respect their decisions.
Regarding his previous comments on the use of "social sanctions" against those who insulted the monarchy, Gen Paiboon said the meaning of his social sanctions is different from mob rule or vigilantism.
He said mob rule is deemed to be against the law, but social sanctions must not break the law.
"No one has the right to harm anyone because this is against the law," Gen Paiboon said. "Social sanctions should be used alongside law enforcement by authorities."
Meanwhile, the government is monitoring and tracking about 100 people who have been accused of posting inappropriate content deemed to insult the monarchy through video-sharing sites and social networks.
According to the Minister of Digital Economy and Society ACM Prajin Juntong, these people have to stop posting, sharing or making comments or they will be charged as suspects who have committed acts deemed defamatory to the royal family.
There are two laws to deal with those who insult the monarchy. They are Section 112 of the Criminal Code, known as the lese majeste law, and the Computer Crime Act.
ACM Prajin said there are now almost 600 web pages that contain inappropriate content deemed to insult the monarchy. Of them, almost 200 web pages have been blocked.
The government set up a war room on Wednesday to monitor and block inappropriate web pages. It is a collaboration between the Cyber Security Operation Centres of the ministry which has 30 staff members and the Centre of the Technology Crime Suppression Division which has 60 staff members.
However, ACM Prajin accepted that the government has to take almost two weeks to block websites that have inappropriate content because they have been encrypted. The government has to file a case with the courts before a court order can be sent to internet service providers to block the websites.
In another development, The United Nations High Commissioner for Refugees has joined the UN Community in reiterating its heartfelt condolences at the passing of His Majesty the King, "whose legacy of good work, devotion to duty and compassion for people stands now and in the future as a model not just for Thailand but for the world".