CAIRO: Egyptian authorities have arrested the "mastermind" behind the sectarian violence in Cairo that killed 12 people, the cabinet said.

"The interior ministry has arrested the mastermind behind the clashes between Muslims and Christians in Imbaba," the cabinet said on its Facebook page late on Monday, without identifying the person.

The authorities also detained another 14 people in connection with the deadly clashes, it said, bringing the total number of arrests to 205.

Around 1,000 Copts continued a sit-in in front of the state television headquarters for a third straight day on Tuesday to protest against sectarian violence and to demand protection.

Some pitching tents, others keeping warm under blankets, the protesters have vowed not to leave until their demands are met.

Fierce clashes broke out Saturday between Christians and Muslims in northwest Cairo's working-class district of Imbaba which also left scores injured and a church ablaze.

Six Muslims and four Christians were among the 12 dead, while two bodies were not identified.

The two groups clashed after Muslims attacked the Coptic church of Saint Mena in Imbaba to free a Christian woman they alleged was being held against her will because she wanted to convert to Islam.

The military council governing Egypt since a popular uprising toppled president Hosni Mubarak admitted that the latest flare-ups in the country represent a “counter-revolution” by old regime diehards aimed at sowing chaos.

Copts, who account for up to 10 percent of the country's 80 million people, complain of discrimination and have been the targets of fairly regular sectarian attacks.

Claims that Christian women who converted to Islam were kidnapped and held in churches or monasteries have soured relations between the two communities for months.