(CNN) -- Government officials in Alexandria, Egypt, increased security around places of worship following an explosion that killed at least 21 people at a church in the region, the governor told state media Saturday.
"We are stressing now on guarding churches," Adil Labib, the governor of Alexandria, told state-run Nile TV.
Evidence indicates that a suicide bomber caused the blast, the country's interior ministry said.
Even though the scene of the explosion was blocked off, protesters carrying crosses gathered near the scene, Nile TV reported.
Authorities believe the bomber was killed in the blast, the interior ministry said in a statement. Forensic testing confirmed that the explosive device used was homemade and contained nails and ball-bearings, according to the statement.
Egypt's health ministry said 79 people were wounded in the attack in Alexandria, the country's official Middle East News Agency (MENA) reported. Four of them were police officers posted outside the church to protect the Christians worshipping inside, the interior ministry said. CNN
