WICKENBURG, Ariz. -- A man who pulled a grenade from his waistband during a traffic stop in Wickenburg sparked an evacuation Saturday morning at a McDonald's restaurant packed with morning diners.

An Arizona Department of Public Safety said the incident began when a DPS officer spotted a vehicle driving recklessly in Wickenburg.

The officer made a traffic stop and pulled the vehicle over in a McDonald's parking lot.

When the driver, identified as Jose Santos Cruz, stepped out of the car, he pulled out the grenade, DPS said.

The DPS officer managed to wrestle the driver to the ground and warned those inside to take cover until the bomb squad could clear the scene, investigators said.

Employees and customers were told to gather in an area of the restaurant away from any windows.

The bomb squad recovered the grenade and determined that it was active. Had the pin been pulled, it would have exploded, DPS said.

Cruz, an illegal immigrant from El Salvador, was booked into the Fourth Avenue Jail on charges of driving under the influence, theft and aggravated assault of a police officer.

A check of the vehicle showed it and the license plate had been stolen in the Phoenix area, DPS said.