Detective Chief Inspector John Caldwell is in a critical condition
Two further arrests have been made by detectives investigating the attempted murder of Detective Chief Inspector John Caldwell in Omagh, Co Tyrone.
Tonight marks a week since the suspected New IRA gun attack.
The PSNI officer remains critically ill, but stable, in hospital.
A 33-year-old man was arrested in Omagh, while a 57-year-old man was arrested in Belfast earlier today.
Both were arrested under the Terrorism Act.
Two men, aged 47 and 71, also arrested in connection with the attempted murder, remain in police custody at this time.

Missing Naas Woman Deborah Doyle Located "Safe And Well"
Over 9,000 Tusla Referrals Linked To Poor School Attendance Were Made Last Year
Homelessness Figures Reach Another Record High, With Numbers Also Increasing In Kildare
No First Home Scheme Increase For Kildare As 17 Areas See €25k Rise
New Year Brings Fresh Fuel Price Hikes For Motorists
Number Of Second-Hand Homes On The Market Drops Sharply
Nearly 4,000 Vehicles In Kildare Deemed Unsafe Following NCT Tests Last Year