Photo taken on April 9, 2017 shows the site of a bomb blast at Mar Girgis Church in Tanta, Egypt.(Xinhua/Ahmed Gomaa)
Egyptian President Abdel-Fattah al-Sisi declared in a televised statement on Sunday evening a three-month state of emergency in the Arab country.
The announcement came hours after two deadly blasts in northern Egypt, which left at least 44 dead and more than 120 injured, mostly worshippers observing Palm Sunday.
The bomb attack at Mar Girgis Church of Tanta city in Gharbiya Province left at least 27 dead and 78 wounded, while the following suicide bombing at Saint Mark's Church of the coastal city of Alexandria killed 17 and injured 48, according to the Health Ministry.
Later on Sunday, the Islamic State (IS) group claimed responsibility for the twin church bombings on its so-called "Amaq" news website.
Al-Sisi expressed in a statement his strongest condemnation and offered condolences to the families of the victims. The president also announced a three-day mourning for the victims.
"This treacherous terrorism targets the nation with its citizens, both Copts and Muslims, and it will never break the determination of the Egyptians and their true will to confront the powers of evil," al-Sisi said in the statement.
For his part, Egyptian Prime Minister Sherif Ismail denounced the "low terrorist plot that targets the security of Egyptians and the stability of the nation," reassuring that the government will provide all necessary support for the victims and their families.
Pope Tawadros II, the head of Egypt's Orthodox Church who was at the attacked church in Alexandria shortly before its blast, showed understanding of the state's anti-terror efforts.
"Egyptians are united in one trench in the confrontation of black terrorism until it is eliminated," the pope said in a statement following the bombings.
Cairo-based Al-Azhar, the highest Islamic learning institution in Egypt and the Sunni Muslim world, rejected the church blasts as "a horrible crime against all Egyptians."
On Sunday, Iranian Foreign Ministry strongly condemned the twin bomb attacks in Egypt, Press TV reported.
"Such criminal measures are planned and implemented in order to incite sectarian strife and create terror and division among followers of divine religions," Iranian Foreign Ministry Spokesman Bahram Qasemi was quoted as saying.
In the United Arab Emirates, Minister of Foreign Affairs and International Cooperation Sheikh Abdullah bin Zayed Al-Nahyan also strongly condemned the terrorist attacks, saying the Gulf Arab state "is standing by the side of the brotherly nation in confronting this criminal and malicious act."
King Abdullah II of Jordan and Lebanese President Michel Aoun both sent a cable to al-Sisi to condemn the church attacks and voice their countries' solidarity with Egypt.
Algerian Foreign Ministry Spokesman Abdelaziz Benali Cherif described the twin attacks as "despicable" and encouraged "strong determination and required means" to handle terrorism.
Qatar and Turkey, which Egypt criticizes for supporting and sheltering members of its blacklisted Brotherhood group, also condemned the church attacks and extended their condolences.
In the United States, President Donald Trump condemned Egypt's bombings on his twitter account.
"So sad to hear of the terrorist attack in Egypt. U.S. strongly condemns," He tweeted, expressing "great confidence that President al-Sisi will handle situation properly."
Russian President Vladimir Putin also condemned "the brutal attack" and offered condolences to the Egyptian president, state-run news agency Tass reported.
