Egyptian authorities further blamed that there are several militants' camps running in Libya which it targeted with the airstrikes on Saturday.
Saudi King Salman bin Abdulaziz, in a phone call with Egyptian President Abdel Fattah el-Sisi, reaffirmed that his kingdom stands in solidarity with and supports all efforts spent by the Egyptian government on reigning in terrorism.
Sisi's remarks came as Trump denounced the attack as "merciless slaughter", saying in a statement, "The bloodletting of Christians must end, and all who aid their killers must be punished."There have been a number of attacks on Coptic Christians in the country in recent months claimed by IS militants". The attacks left over 75 dead and scores wounded. The exact location of Friday's airstrikes was unclear, but Nile TV reported that Egypt has targeted terrorists in the Sinai Peninsula and on the border with Libya.
"The aim of the terrorists is to split Egypt into two countries, one Christian, and another Muslim".
This is the first official response by the Coptic Orthodox Church after unknown assailants on three 4x4 vehicles attacked a bus carrying Coptic Christians on the way to Saint Samuel Monastery in the east of Minya governorate. Egypt has repeatedly expressed concern over militants crossing from Libya to carry out attacks.
The Copts follow the teaching of Apostle Mark, who introduced Christianity to Egypt, according to St. Takla Church in Alexandria, the capital of Coptic Christianity.
Two deadly church bombings in Alexandria and Tanta took more than 45 lives in April, and almost 30 people were killed in the Daesh-claimed attack on a church in the capital Cairo in December.
In December an IS suicide bomber attacked another church in Cairo, killing 29 people.
"Terrorists are engaged in a war against civilisation, and it is up to all who value life to confront and defeat this evil", US President Donald Trump said in a statement.
Following the Palm Sunday bombings, Sisi declared a nationwide three-month state of emergency.
"They chose death", said Makarios, who has been an outspoken critic of the government's handling of anti-Christian violence in Minya, where Christians account for more than 35 percent of the population, the highest anywhere in Egypt.
In past attacks, Egypt had usually identified local jihadists as the perpetrators.