Two parishioners and a pastor at one of the churches told Human Rights Watch that police protection at the church gate was inadequate and may have allowed the bomber to enter.
The Egyptian authorities have consistently failed to prosecute those responsible for sectarian attacks against Christians, resorting instead to state-sponsored reconciliation agreements which sometimes involve financial agreements or even the forced eviction of Christian families from their homes.
"Parliament Speaker Ali Abdel Aal has announced the assembly's unanimous approval of the state of emergency", state television reported.
"Where is the government?" said Maged Saleh, whose mother was able to escape the blast at the St. George's Church in Tanta. Albawaba newspaper, an Egyptian daily newspaper, stated that an hour after the state of emergency was declared the authorities confiscated its Monday edition due to its coverage of the church attacks.
In May 2011, clashes between Muslims and Copts left 15 dead in the Cairo neighborhood of Imbaba, where two churches were attacked.
El-Sissi has clamped down on opponents since he led the military overthrow of an Islamist president, Mohammed Morsi, who was elected in 2013.
The government's persistent failure to protect Coptic Christians from sectarian violence is alarming.
Trump called Sisi a "fantastic guy" and the Egyptian president was the first foreign leader to congratulate Trump after his victory in November.
On April 11, parliament voted unanimously to approve al-Sisi's decree.
Egypt's emergency law, which dates to 1958, gives the authorities sweeping powers to arrest, detain, try, and sentence suspects with nearly no judicial review.
"The powers that the security agencies have already don't need reinforcement by the state of emergency", Abdel-Aziz said.
"Despite the terror blasts, terrorism in Egypt in general and in Sinai in particular is declining, which shows success of the security forces in their anti-terror war, and this is why the terrorist moved to target Copts", said the security expert, noting that there is no such a thing as 100-percent security against a suicide bombing in any state across the world. "You noticed that I am not using another word than Egyptians. we are the Egyptians".
The 2013 ruling annulled an important article of the law, which gave the president the right under a state of emergency to instruct the interior minister to conduct arrests without warrants as well as administrative detentions. There are a lack of prosecutions and people not being held to account.
Both churches were protected with some form of security, he adds.
The next month, security forces used deadly force to break up two pro-Morsi protest camps in Cairo.
"I just want to let everybody know in case there was any doubt that we are very much behind President Sisi", Trump said.
"We apologise that we will not be receiving felicitations from officials or regular citizens".
Under worldwide law, governments may declare a state of emergency when there is a "public emergency that threatens the life of the nation", but the emergency restrictions must be proportionate and limited to the greatest extent possible in both time and area.