Germany's Coptic Christians have received threats of attack by radical Muslims and asked for protection, a bishop said in a newspaper Sunday, as Egypt's Coptics reeled from a massive bombing.

"The Internet is full of threats of this kind against us. The police have alerted us several times against attacks by radical Muslims," Coptic Bishop Anba Damian said in a report on the Bild's online edition.

The threats rose over the end of year festive season, he said.

"I have written to the interior minister to ask for protection," the bishop said.

A blast apparently caused by a suicide bomber struck a Coptic church in Egypt's northern city of Alexandria on New Year's Day Saturday, killing 21 people and wounding 79.