At least 27 people have been killed in an explosion inside a church in the Egyptian Nile Delta city of Tanta, local media reported, as state television said another blast killed 16 in front of a church in Alexandria.
The Islamic State of Iraq and the Levant (ISIL, also known as ISIS) armed group on Sunday claimed responsibility for both attacks, in a statement via its Amaq website.
The first attack occurred in the Coptic church of Mar Girgis, also known as St George, which was packed with worshippers marking Palm Sunday, a Christian feast commemorating the entry of Jesus Christ into Jerusalem.
Egypt's state television reported that at least 69 people were wounded in the attack.
Several hours after the bombing in Tanta, another explosion hit in front of Saint Mark's church in Alexandria, killing at least 16 people, according to the health ministry.
Media reports said dozens were wounded in the attack, which state TV said was a suicide bombing.
Mahjoob Zweiri, associate professor at Qatar University, told Al Jazeera that Tanta has seen several attacks in the past.
"The area and Christians both have witnessed such accidents before. There is a good percentage of Christians in this area and other non-Muslims too," Zweiri said.
"I believe when there are such religious events in the country, authorities should take security measures into consideration as there are always chances of attacks," he added.
Timothy Kaldas, non-resident fellow at the Tahrir Institute for Middle East Policy, said the attacks were designed to create religious strife.
"It is alarming to see a specific religious group being targeted, which is going to rattle the Coptic community and many Egyptians in general," Kaldas added.
Copts repeatedly targeted
The bombings were the latest in a series of assaults on Egypt's Christian minority, who make up about 10 percent of the population and have been repeatedly targeted by armed groups.
They also come just weeks before Pope Francis is due to visit Egypt.
CBC TV showed footage from inside the church in Tanta, with a large number of people gathered around what appeared to be lifeless, bloody bodies covered with papers.
A bombing at Cairo's largest Coptic cathedral killed at least 25 people and wounded 49 in December, many of them women and children, in the deadliest attack on Egypt's Christian minority in years.
Source: Al Jazeera News