Following Berlin Attack, What You Can Do to Stay Safe While Holiday Shopping

Security has been beefed up in areas of New York City, especially around Christmas markets, following the terrorist attack in Berlin Monday.

Read: 12 Dead After Truck Plows Into Christmas Market, U.S. Says it 'Appears to Have Been Terror Attack'

Twelve people were killed and 48 were injured at a Christmas market in the German capital after a stolen truck was used a weapon to shatter peace and joy.

Like what the world saw in July during the Bastille Day attack in Nice, France, the truck barreled through the crowd.

Former New York Police Commissioner Bernie Kerik gave Inside Edition tips on how to stay safe.

"Most importantly, they have got to watch their surroundings. Look for exit routes; look for ways to get out once you get in. Look for suspicious people, suspicious packages," he said. 

American Shandana Durrani was at the Berlin Christmas market during the attack. She says a text message may have saved her life.

“I saw everything,” she told Good Morning America Tuesday. “I looked down to take a text and when I looked up I saw the truck, we took refuge behind a stall because we did not know if there was gunfire or not.”

Read: Brazilian Soccer Player Credits Seat Change for His Survival in Crash that Killed 71 Others

The attack came on the same day as the shocking caught on tape assassination of the Russian ambassador to Turkey in the city of Ankara. The U.S. State Department website has a "Europe travel alert" for Americans going oversees during the holidays.

It has a warming that reads: “U.S. citizens should exercise vigilance when attending large holiday events.”

As well as telling tourists to “Stay in touch with your family members and ensure they know how to reach you.”

Watch: After 'Supermom' Jogger's Kidnap Ordeal, How Your Smartphone Can Keep You Safe