Egypt's President Abdul Fattah Al-Sisi has declared a three-month state of emergency after attacks on two Coptic churches that left at least 44 dead, a report said.

The declaration allows authorities to make arrests without warrants and search people's homes, BBC reported.

Sisi warned that the war against the jihadists would be "long and painful", and said that the state of emergency would come into force after all "legal and constitution steps" were taken.

In Alexandria, an explosion outside St Mark's Coptic church killed 13 people. Pope Tawadros II, head of the Coptic Church, had been attending Mass inside and was unhurt, an earlier BBC report said quoting state media.

An earlier blast at Mar Gerges church in Tanta killed 27, while 78 others were injured, a Health Ministry spokesman announced.

Twenty-two of the injured were discharged from hospital, it said.

The Islamic State (IS) group said it was behind the explosions. The group has recently targeted Copts in Egypt.

Four police officers, including one policewoman, were among those killed in Alexandria, the interior ministry said. The suicide bomber blew himself up after they stopped him from entering the church.

The first explosion in Tanta, 94 km (58 miles) north of Cairo, took place near the altar.

Security forces later dismantled two explosive devices at the Sidi Abdel Rahim Mosque, also in Tanta, the state-run Al-Ahram news website reports.

Prime Minister Sherif Ismail phoned Pope Tawadros II of Alexandria and Patriarch of Saint Mark Diocese to extend condolences over the victims of the two blasts.

President of Shebin el Kom primary court Counselor Sameul George was among those killed in the attack which targeted Mar Gerges Church in Tanta, said an official.