Center City employees and shoppers were given quite a scare this morning by a man who was ranting and wielding a knife for nearly an hour at 8th and Market streets, police said.

What they didn't see was the hand grenade that police later recovered from his bag.

Witnesses said that the man, with the knife pulled, began ranting on the sidewalk shortly after 8 a.m., but police weren't contacted for nearly an hour, said police spokeswoman Officer Tania Little.

When police arrived, they saw the man threatening passers-by with a large army knife. Authorities detained the man and found a hand grenade inside a camouflage backpack he wore, Little said.

Members of the bomb squad were alerted and the surrounding area was closed down, Little said. The grenade was later determined to be a practice round.

The man, who has not been charged, was taken to Pennsylvania Hospital for psychiatric evaluation. *