Sri Lanka has deployed thousands of troops to help police search for suspects. (File)
Sri Lankan security officials ordered a lockdown at the central bank on Thursday due to a bomb scare, two bank officials told Reuters, as the street outside the bank, which is near the World Trade Center, was blocked to traffic.
Authorities also shut off the entry road to Colombo's main airport after a suspicious vehicle was identified at a nearby car park.
Easter suicide bomb attacks on Sunday claimed by the ISIS killed nearly 360 people and injured over 500.