CAIRO The death toll from a New Year bombing outside a church in the Egyptian city of Alexandria has risen by two to 23, the official news agency MENA said on Tuesday.
Dozens of people were wounded when a presumed suicide bomber detonated a device during a midnight service.
No clear official account has emerged of how the attack was carried out but political analysts point to a small cell, not a large militant group such as those behind an Islamist insurgency that flared more than a decade ago.
A Health Ministry official said 18 bodies had been identified but put the possible number of dead at 22, based on studies of body parts found at the scene.
Billionaire Naguib Sawiris, chairman of Orascom Telecom, one of Egypt's biggest listed companies, has offered 1 million Egyptian pounds ($172,500) for information on those behind the January 1 attack, a state newspaper said on Tuesday.
The Dutch anti-terrorism agency NCTb has urged police to keep an eye on Coptic churches in three Dutch cities after they were included in Internet threats against Coptic churches in Europe, including France and Britain.
The bombing provoked protests and some clashes with police in Alexandria and the capital, Cairo, by young Christians calling for more protection.
Christians account for about 10 percent of Egypt's population of 79 million, which is mostly Muslim. Sectarian violence is rare but disputes on issues from church building to religious conversions and divorce have grown in the past year.
Early last year, a drive-by shooting of six Christians and a Muslim policeman at a church in southern Egypt led to protests.
Egyptian officials have said there are indications "foreign elements" were behind the January 1 blast. An Iraqi group linked to al Qaeda threatened in November to attack Egyptian Christians.
(Reporting by Shaimaa Fayed; Additional reporting by Sherine El Madany and Amsterdam bureau; Editing by Andrew Dobbie)