"We are reciting a very powerful prayer to summon the Lord to help our country," said Sumitr Khorana, a Hindu community leader, reflecting a general anxiety that Thailand's turmoil is far from over.
"Things are quiet now but there is fear still within us because none of us know what can happen in the future."
The ceremonies come a day after Thai authorities accused Thaksin Shinawatra, the prime minister deposed in a 2006 coup, of terrorism and issued an arrest warrant on charges that carries a death sentence.
Al Jazeera's Alan Fisher, reporting from Budva in Montenegro, said Thaksin had been at his home in Montenegro when Thai authorities launched what they described as an international manhunt, enlisting the help of international police organisation, Interpol, and the former prime minister left the country soon after that.
"All European countries have said that they will not accept him. In Dubai they said they were willing to have him on their soil but he must not engage in political activities while he's there.
"But what is likely is that he will return to Montenegro because the country has never extradited a citizen, and as a citizen Thaksin has that protection," our correspondent said.
Montenegro granted Thaksin citizenship this year.
Thaksin, who fled abroad ahead of a corruption conviction he claims was politically motivated, is accused of being the main force behind the red shirts.
The former prime minister said on his Twitter page on Tuesday that he did not "want to see Thailand turn into a banana republic, where one guy's free to just push any button in the system and destroy whatever justice and credibility it has".
"Don't go around telling the world that you're a democratic country. Be ashamed," he said.
Sukhumbhand Paribatra, the governor of Bangkok and a member of the ruling Democrat party, told Reuters Television that Wednesday's religious ceremonies were meant to "wipe away a bad path and to create a better future".
"It is very important for all of us in Bangkok to forgive and move ahead," he said.
But analysts say without major reforms to address claims of marginalisation from the rural poor – who form the bulk of the red shirts - such prayers and forgiveness will not end a polarising crisis that has cost the country at least 85 lives and the economy billions of dollars.