0121 GMT December 19, 2018
Ten people died when gunmen tried to storm a church south of Cairo, but were intercepted by police, BBC wrote.
About an hour later, a Coptic-owned shop in the same area was attacked, leaving two dead.
More than 100 Christians have been killed in Egypt in the past year — most attacks claimed by the local branch of the Daesh terror group.
Security forces have put checkpoints in place around the capital in response to the attacks.
They announced plans earlier this week to protect festivities around the New Year and Coptic Christmas. They include the deployment of rapid-reaction forces and jamming equipment.
Friday's first attack appears to have taken place when police patrolling the church noticed two men behaving suspiciously.
They approached the men, who began firing.
Among the dead were three police officers who were on duty at Mar Mina church. There are reports that several people were wounded, two critically.
Last April at least 45 people died in twin attacks on Coptic churches in Alexandria and the Nile Delta city of Tanta. At least 29 Copts were killed on a bus en route to a monastery in central Egypt in May and a Coptic Orthodox priest was stabbed to death in Cairo in October.
The attacks have been blamed on, and in many cases claimed by Daesh.
Six Egyptian soldiers died when their vehicle exploded during a raid against "terrorists" in restless North Sinai, the army said Thursday.
"An officer and five soldiers died when an explosive device blew up their vehicle during a raid on a terrorist den," spokesman Tamer al-Rifai said in a statement.
In a separate operation, three gunmen were killed, he said, adding that they were in possession of weapons, ammunition and explosive devices.
Four vehicles belonging to the cell were also destroyed, killing the passengers inside.
He did not specify the date of either incident.
Terrorists also killed two people, including a policeman, at a bank in the town of El-Arish in Egypt’s North Sinai on Thursday.
Terrorists have escalated their attacks on security forces since the ouster of former president Mohamed Morsi in 2013.
They are particularly active in North Sinai where a wing of the Daesh terror group has a presence.
Hundreds of police and soldiers have been killed.
In November, suspected Daesh gunmen killed more than 300 Muslim worshippers at a mosque in Sinai.
After the mosque attack, President Abdel Fattah al-Sisi instructed his military chief of staff to quell the attacks in three months using "brutal force".