The plot, if not thwarted by the innocent victim and swift response from security officials on Tuesday, would have caused huge casualties.
Police and soldiers staged pre-dawn operations Friday to make the arrests. The suspects are Sanafee Jehteh, 29, Marorfee Jehdeemae, 42, and Reeduwan Tahay, 32.
DNA traces from the pickup used in the foiled bomb plot have already nailed down one of these suspects.
Police are now interrogating these suspects in a bid to track down all involved. According to witnesses, about 10 men had taken part in the pickup hijacking.