An explosion outside a church in Egypt killed at least 21 people early Saturday, state media said.
Egypt's health ministry said 79 people were wounded in the attack in Alexandria, the country's official Middle East News Agency (MENA) reported.
State-run Nile TV showed firefighters battling a blaze at the scene.
A car parked in front of the Church of Two Saints exploded shortly after midnight, Egypt's interior ministry said. Coptic Christians were attending services there at the time of the blast, Nile TV reported.
The car was filled with explosives, Nile TV reported, citing the interior ministry.
A nearby mosque was damaged and eight Muslims were among the wounded, the interior ministry said.
Alexandria Gov. Adel Labeeb told Nile TV that samples from the scene had been sent to a government lab as part of an investigation.
"The attack targeted all Egyptians and not just our Coptic brethren," Labeeb said, according to MENA.
Egyptian officials are blaming foreign elements for the attack, MENA reported.
Copts, who are adherents of an Egyptian sect of Christianity, make up about 9% of the nation's population. About 90% of Egyptians are Muslims.
Al-Azhar, one of Egypt's oldest centers of Islamic study and worship, issued a statement condemning the attack.
"This is a criminal act that can never be justified (in) any religion. Islam specifically prohibits any attacks on religious places. As a matter of fact, it tasks Muslims with protecting religious places of worships for Muslims and non-Muslims," Al-Azhar spokesman Mohammed Tahtawi told Nile TV.
In November, a group with ties to al Qaeda in Iraq announced that all Christians in the Middle East would be "legitimate targets."
Shortly after the message was released, Egyptian police sources confirmed that security had been reinforced at churches around the country and additional protection was being provided to the head of the Coptic Church, police said.
Tensions have been running high between Egypt's Muslim majority and minority Christians.
The U.S. Commission on International Religious Freedom said in November that 10 Coptic Christian homes and several businesses were burned and looted in Qena province in southern Egypt following rumors of a romantic relationship between a Christian man and Muslim woman. Security officials imposed a curfew and arrested several Muslims, the commission said.