MEXICO CITY (AP) _ Sparks from a fireworks display apparently fell on other fireworks, setting off an explosion that killed four people, injured 15 and badly damaged a church on Wednesday, officials said.

The government's Notimex news agency quoted the Mexico State attorney general's office as saying more than 1,700 fireworks blew up in Santa Ana Jilotzingo during a religious festival celebrating the end of a pilgrimage to a nearby shrine.

It said eight of the injuries were serious, Notimex reported.

Mexico City television stations broadcast images of the badly damaged church against which the fireworks had been kept _ two of its walls blown out and an interior scarred by flying debris.

Santa Ana Jilotzingo is about 15 miles west of Mexico City.