Several churches and monasteries in Egypt are built on sites Copts believe were visited by the Holy Family. In Alexandria, 18 civilians and four police officers were killed when a suicide bomber blew himself up outside a Coptic church, Al-Ahram said.
It said security forces were "pursuing efforts" to identify a second attacker who targeted the other church in Tanta hours, killing 28 worshippers. IS claimed both bombings. He recalled watching his son wearing white vestments and singing at the service.
The Secretariat said Muslims are standing with the whole world in denouncing and condemning it.
Photos of the elder Maher, sitting helplessly in his blood-stained vestments after the bombing, were widely circulated online.
On Sunday, the Rev. Danial Maher buried his 23-year-old son, Beshoy.
In October 2011, nearly 30 people - mostly Coptic Christians - were killed outside the state television building in Cairo after the army charged at protesters denouncing the torching of a church in southern Egypt. In December, a suicide bombing claimed by an IS affiliate killed 29 people during Sunday mass in Cairo.
According to the Egyptian constitution, any state of emergency must be confirmed in parliament by majority vote within seven days of its declaration by the president. The Cabinet declared that it had gone into effect at 1 p.m. (1100 GMT).
In theory, it allows for arrests without warrants, the swift prosecution of suspects and the establishment of special courts. However, given the power he already has, it's not certain what additional authority he's seeking from the move.
"We were deeply shocked by heavy casualties and injuries as a result of a series of blasts in your country", said President Aliyev in his letter of condolences. "It's a purely political decision that is meant to have a psychological impact".
Egypt has been fighting a terrorist wave that killed hundreds of policemen and soldiers since the military removed former Islamist President Mohamed Morsi in July 2013 and blacklisted his Muslim Brotherhood group as "a terrorist organization".
The emergency law "will give the state bodies the needed flexibility and speed to fight a vicious enemy", Ismail said.
Two Coptic Orthodox churches were the targets of Islamic State bombings on April 9, Palm Sunday.
The American president announced in his daily press meeting his deepest condolences in behave of the American nation and issued: "So sad to hear of the terrorist attack in Egypt".