By Greg Argos

PHILADELPHIA (CBS) — An investigation is underway after a handful of pizza delivery drivers were violently robbed in Philadelphia. Police don’t believe the incidents are related, but they say all of the attackers were armed.

Delivering an extra-large pizza with pepperoni shouldn’t come with the threat of robbery. But that’s what happened to at least three different pizza delivery drivers at three different shops so far this month.

“Not only do they take their money, sometimes they take their cars, they take the food,” Philadelphia Police Capt. John Walker said.

The latest incident took place Monday night on the 6800 block of Erdrick Street in Mayfair. Police say a Pizza City driver was robbed of his wallet, phone and food around 10:20 p.m.

“He was approached by five guys,” Abe Omar, owner of Don Giovanni’s, said. “Three guys from the back, two from the front.”

Man In Easter Bunny Suit Involved In Florida Brawl Wanted In New Jersey For Car Burglaries

Someone robbed Omar’s driver at gunpoint on April 10, just blocks from the Don Giovanni pizza shop he owns off of Castor Avenue.

“Stuck him up and took the money,” Omar said.

The driver, a 17-year-old, quit shortly after the incident. Moheeb Awad is his twin, who still works deliveries.

Credit: CBS3

“He went home and he didn’t sleep,” Awad said.

A third robbery happened in Port Richmond on April 7, and though investigators say they’re not connected, they have released delivery safety tips for restaurants in the city.

“We sent fliers out to the businesses alerting them to things they can do today with technology,” Walker said.

Thousands Of Child Sex Abuse Cases Listed In Boy Scouts ‘Perversion Files,’ Attorney Says

Like checking addresses on Google Earth, and using a caller ID system to track fake or masked numbers. All good pieces of advice, but Omar says staying vigilant is the key.

“You got to watch out. If you aren’t careful, it could happen,” Omar said.

Police have not made any arrests in any of the three cases. If you have any information, you are asked to call police.