Two women, aged 25 and 27, and a man aged 51 years old, were arrested under section 41 of the Terrorism Act 2000.
They were taken to Musgrave Serious Crime Suite for questioning.
Police say all three have now been released and the investigation continues.
The 27-year-old was released pending a report to the Public Prosecution Service.
A property in Strabane was also searched and a number of items were seized.
One man is currently remanded in custody over the bomb murder bid.
The New IRA later responsibility for the attack.
Police are appealing to anyone with information to contact them on 101.
Additionally, information and media can be provided to police through the Major Incident Public Portal link: https://mipp.police.uk/operation/PSNI22A02-PO1
Information can also be provided to Crimestoppers anonymously on 0800 555 111 or online at www.crimestoppers-uk.orgTags: