In a six-page document released to truck and bus companies last week, the TSA highlighted 17 incidents that have killed more than 170 people around the world since 2014.
Most happened in Jerusalem (four) or Europe (10), including a July attack in which a man drove a truck into pedestrians in Nice, France
, killing more than 80 people during a Bastille Day celebration.
• November 2016: A man drove a car into a group of people at Ohio State University
and charged at passersby with a knife in November, injuring 11.
• October 2014: An attacker rammed a car into two Canadian military personnel
outside a strip mall in Saint-Jean-sur-Richelieu, Quebec, killing one and injuring the other.
But people in the US need to be vigilant, the TSA said, asserting terrorist groups probably will "continue to encourage aspiring attackers to employ unsophisticated tactics such as vehicle-ramming, since these type of attacks minimize the potential for premature detection and could inflict mass casualties if successful."
"These low-tech methods of attack are becoming more commonplace around the globe," the TSA said in a statement released Thursday.
Businesses should take measures to prevent the theft of commercial motor vehicles and watch for suspicious behaviors by those who might want to rent or buy such vehicles, the report says.
The most recent attack highlighted in the report happened last month: A truck was driven into pedestrians on a street in Stockholm, Sweden
, before it crashed into a department store; four people were killed.
Terror groups overseas have advocated ramming attacks for years. In a 2010 webzine article, for example, Al Qaeda's Yemeni branch encouraged Western recruits to use trucks as "a mowing machine
, not to mow grass but mow down the enemies of Allah."