Security was tight on Friday night as thousands of Coptic Christians gathered for a Christmas Eve Mass at the Abbassiya Cathedral in the Egyptian capital of Cairo. There were calls among Coptic followers to keep the celebrations low-profile this year.

This is the first Christmas after last year's revolution, which dislodged former President Hosni Mubarak.

In the last two years, there were riots and attacks targeting the Coptic Christian community. On New Year's Day 2011, at least 21 people were killed and more than 70 injured in a suspected suicide bomb attack targeting the Al-Qiddissin (The Saints) church in Alexandria. The previous year, six Copts were killed when they exited a church in southern Egypt after attending a Christmas Eve mass.

This year, many Islamist leaders attended the mass led by Pope Shenuda III in Cairo.

Secular activists held a candlelight vigil outside several churches with the slogan: "We all celebrate together as Egyptians."

The Maspero Youth Union, a Coptic group, in a Facebook statement, had urged the church to keep the celebrations low-profile as a mark of respect to people who died in last year's anti-government protests. Dozens of Coptic followers were killed during the protests.

The midnight Christmas Eve mass was advanced this year for security reasons.

Members of the Freedom and Justice Party, the political arm of the powerful Muslim Brotherhood, attended the ceremony. The Freedom and Justice Party has emerged as the leading force in the first post-revolution parliamentary elections in Egypt.

The Copts celebrate Christmas on Jan. 7 as per their ancient calendar. There are an estimated 5 million to 15 million Coptic Christians in Egypt, which means they represent about 10 percent of the population. They have been a target of the majority Muslim population and often allege that they are marginalized in the country's political system and in other spheres.