Egypt's Sisi declares three-month state of emergency
Sisi announced the "state of emergency for three months" in a defiant speech at the presidential palace after a meeting of the national defence council.
Under the country's constitution, Sisi will have to put the measure before parliament, which is stacked with his supporters, for approval within a week.
The emergency law expands police powers of arrest, surveillance and seizures and can limit freedom of movement.
The army chief-turned-president also announced the founding of the "Supreme Council to Counter Terror and Extremism", a new security apparatus aimed at combating a growing militant insurgency in the country.
Sisi then urged media outlets to be "careful" in their coverage of the events that "hurt the Egyptian people", adding that the parliament should address the religious discourse in the coming period.
At least 43 people were killed in the bombings in the Nile Delta cities of Tanta and Alexandria, which happened as worshipers were gathering to mark Palm Sunday.
The Islamic State group has claimed two Egyptian suicide bombers carried out both attacks and threatened further attacks in a statement published on social media.
US President Donald Trump condemned the attack and said in a tweet that he had "great confidence" that Sisi "will handle the situation properly".
Trump's tweet and his recent meeting with Sisi in Washington despite the Egyptian regime’s abysmal human rights record could signal a US green light for an unprecedented crackdown.
Pope Francis is due to visit Cairo on 28-29 April to show solidarity with Egypt's Christian community. Some experts have said the attack may be an attempt to force a cancellation.
Critics fear the new state of emergency would be used by the Egyptian regime to crackdown on political opponents and expand extrajudicial killings, enforced disappearances, without stopping terrorist attacks.
Egypt has been battling a growing Islamist insurgency, in which hundreds of Egyptian security personnel have been killed, since the ousting of Islamist President Mohamed Morsi in a 2013 military coup, led by then defence minister Sisi.
Most of the attacks have taken place in north Sinai, which borders Israel and the Palestinian Gaza Strip, though attacks have reached Cairo.
Copts, who make up about one tenth of Egypt's population of more than 92 million and who celebrate Easter next weekend, have endured successive attacks since Morsi’s ousting.
More than 40 churches were targeted nationwide in the two weeks after the deadly dispersal by security forces of two pro-Morsi protest camps in Cairo on 14 August that year, Human Rights Watch said.
In December, a suicide bombing claimed by the Islamic State group killed 29 worshippers during Sunday mass in Cairo.