MILAN -- The Uffizi Gallery in Florence was struck by lightning before dawn Thursday, setting off alarms that drew both firefighters and anti-terror police. No damage was caused to either the structure or the artworks it contains.

Director Eike Schmidt said the emergency services and anti-terror police arrived within minutes of the alarms, just after 5 a.m. Thursday.

The lightning strike activated extinguishing powder in the prints and drawings storage area, but no artwork was damaged, he said.

The museum's opening was delayed by 90 minutes. Schmidt said the prints and drawings cabinet will remain closed until Monday for cleanup.

The extinguishing system was installed four years ago, "and went into action just as it should have," Schmidt said in an email. "Although it wasn't of course planned as that, we couldn't imagine a better test for our systems, as well as for the emergency response procedures."

The Uffizi is one of Italy's most-prized and most-visited museums, housing many of the world's masterpieces, including Botticelli's "Primavera" and "The Birth of Venus," and Leonardo's "Adoration of the Magi."