A devastating blast outside a church in the northern Egyptian city of Alexandria was carried out by a suicide bomber, the Interior Ministry said in a statement, dpa reported.
Investigation showed that it was not a car bomb, but a suicide bomber who carried a locally made bomb and probably died in the explosion, the statement, carried by state tv, added.
"Foreign elements were behind planning and implementation of the attack," the statement said.
The attack left 21 people dead and 43 injured, the Ministry of Health said.
Witnesses said earlier that a car that was parked outside the Church of the Saints went off around 20 minutes after midnight, targeting Coptic Christians who were attending a New Year's Eve mass.