Thailand's King Bhumibol Adulyadej has appealed for police and military to work together to restore peace in the Muslim-majority south of the country.
The Thai prime minister hopes paper-folding can promote unity
It was the second time in two days that the highly-revered royal family had commented on the continuing troubles.
King Bhumibol said the violence, which has led to more than 500 deaths this year, threatened Thailand's stability.
He was speaking after a UN official expressed concern at the recent deaths of at least 85 Muslim protesters.
Philip Alston, the special rapporteur of the United Nations Commission on Human Rights, has asked the Thai government to let him visit the country.
In a statement, he said he was "deeply concerned" by the deaths, and by reports that others had disappeared following the protest in the southern town of Takbai in October.
Home to most of Thailand's 4% Muslim minority
Muslim rebels fought the government up to the mid-80s
Suspected militants have upped attacks this year, targeting Buddhists
Security forces' response criticised by rights groups
Most of the dead were suffocated in army custody after they had been overloaded into trucks.
Reprisal attacks by suspected Muslim militants have killed nearly 30 state officials and Buddhist civilians.
The king said, in a televised address, that if military and police officers handled the situation properly, people would be able to live in peace and happiness.
Muslim leaders in the south have long complained about the security forces, pointing out that comparatively few are recruited from the Muslim community.
Thai Prime Minister Thaksin Shinawatra, who has come under mounting criticism for his failure to stop the violence, has launched a campaign to fold 60 million paper birds to promote a message of unity.
The origami birds, made by students, housewives and politicians across Thailand, are to be flown to the Muslim majority provinces on 5 December.
But BBC correspondent Kylie Morris in Bangkok says Muslim leaders are uneasy about the project and would prefer concrete steps from the government to end the violence.
Thailand's southern provinces have for years been associated with low-level violence, variously blamed on Muslim separatists, drug trafficking and the police.
But the violence has sharply escalated this year, with the government blaming separatists educated in Islamic schools abroad.
But others blame the authorities for exacerbating the situation in a poorer region where there has long been a sense of grievance over neglect by the Buddhist majority government, our correspondent says.