Authorities say an acid-filled bottle that sprayed a 10-year-old girl yesterday was the fourth of its kind found in San Mateo County in a month.

The two-liter soda bottle filled with hydrochloric acid was wrapped with duct tape and left outside a Redwood City church.

The bottle exploded when the 10-year-old girl's brother kicked it. The acid doused the girl's legs and melted holes in her nylons.

Redwood City Fire Department officials said the girl was not injured.

Battalion Chief Steve Cavallero said three similar bottles have been found recently in Woodside. He said the incidents may be connected.