- The ceremony was attended by embattled Yingluck Shinawatra
- The government and protesters are in the midst of a temporary truce
In a birthday speech Thursday, Thailand's deeply revered king asked the nation to maintain the peace it has enjoyed "for a very long time" by working hand in hand.
"Our nation has always been in peace for very long time because there is unity in our nation," King Bhumibol Adulyadej said. "Each of us performs our duties in a harmonious manner for the sake of our country.
"Every Thai should realize this, and perform their given duties to benefit the broader public."
The ceremony was attended by embattled Prime Minister Yingluck Shinawatra.
The Thai capital, Bangkok, has seen several days of protests to force Yingluck Shinawatra from office. Those demonstrations took a break this week after the Thai government said it had negotiated a temporary truce with protesters to celebrate the king's birthday.
The world's longest-serving monarch, the king turned 86 on Thursday.
Suthep Thaugsuban, who has led the demonstrations against Yingluck's government in pockets of central Bangkok, said the campaign will resume.
"We will continue fighting until Thaksin's regime is definitively wiped out," he said, referring to Thaksin Shinawatra, the exiled former Prime Minister and brother of Yingluck who is considered to retain considerable influence in Thailand.