Bombs Are Terrorists’ Weapon of Choice on Public Transit

Bombs have been terrorists’ weapon of choice in more than half of all attacks on public surface transportation around the world since 2004. They have also caused more than 60 percent of resulting fatalities and more than three quarters of injuries.

In the third of a series of studies on the frequency and lethality of such attacks between January 2004 and December 2021, the Mineta Transportation Institute’s latest report, The Use of Explosive Devices in Attacks on Public Surface Transportation: Trends in Frequency, Lethality, and Prevention, examines the way bombs were used in 3,836 attacks on passenger train and train stations, buses, bus stations and stops, passenger ferries and terminals, rail infrastructure, and operating and security staff.

Author Brian Jenkins, says, “While the percentage of bomb attacks globally has decreased, we found that lethality has increased, particularly in economically advanced countries, where suicide bombings are the most lethal bomb attacks. Most frequently, bombs were placed inside bus or train compartments, on railway tracks, or inside train stations. The bombs in stations and compartments resulted in the most casualties. However, the majority of attacks in economically advanced countries are unsuccessful, with devices discovered, malfunctioning, or failing to detonate. Despite the decrease in attacks, bombs do remain very lethal—particularly in confined spaces.”

The report shows that bombers had greater success in the other countries, with vehicle-borne explosive devices being the most lethal in developing countries, followed by suicide attackers carrying bombs. Co-author Bruce Butterworth says this may be because explosives are easier to acquire in less developed countries or detection and prevention by authorities are weaker. “Worldwide, successful bombings have declined,” he says. “More bombs are being detected before detonation, particularly in the advanced countries, although the identity of most of the individuals who have found bombs and stopped attacks is unknown.”

The authors’ companion reports: Evolving Patterns of Violence in Developing Countries can be found here. Changing Patterns of Violence Pose New Challenges to Public Surface Transportation in the United States can be found here.