Three men, including a pensioner, arrested following the discovery of a viable explosive device in Strabane have been released unconditionally.
The men- aged 43, 45 and 77- were arrested under The Terrorism Act after a device was found in the Drumrallagh Estate on Sunday.
Ten houses had to be evacuated during the security alert which last for several hours.
Army bomb experts were called to defuse the device.
Under The Terrorism Act, people arrested must be charged, released pending report to the Public Prosecution Service or released unconditionally.