Outside of Upper Mesopotamia - known by its Arab name al-Jezira- other Christians were invited to take part in the muted holiday celebrations. Various Christian denominations make up around 16 percent of Syria's 22.5 million population.
"The invitation to the heads of the Christians communities...is a notable move that has been welcomed in al-Jezira, where it is interpreted as a sign of solidarity with the rebellion and its aims. It is a way to side with the Syrian people'' for peaceful democratic change, unnamed al-Jezira religious leaders told Adnkronos International (AKI).
The United Nations this week said it believes more than 5,000 people have died in clashes since the Syrian Arab Spring uprising began in March. It blames most of the deaths on Syrian government forces. The government led by president Bashar al-Assad routinely says most of the killings were committed by armed gangs and terrorists.
By observing the holiday strictly within religious parameters demonstrates that Syrian Christians are not aligned with al-Assad, according to an activist.
"This is a clear response to those who accuse Christians and their religious leaders of supporting oppression by the regime, Sulayman Yousef, a Syrian anti-government activist and expert on his country's minorities, told AKI.
"It's a message to all members of the nation, Muslim or otherwise, to say that the destiny of Christians is inseparable from the rest of the people," he said.