Northern Ireland police arrested a sixth man on Saturday in connection with the attempted murder of Detective Chief Inspector John Caldwell.
A 71-year-old man was detained in Omagh under the Terrorism Act and was taken to Musgrave Serious Crime Suite to be questioned by detectives, the Police Service of Northern Ireland said in a statement.
Five men aged 22, 38, 43, 45 and 47 arrested earlier in connection with the attack remain in police custody.
Caldwell, a serving police officer for 26 years, is in critical condition after undergoing surgery.
He was shot a number of times on Wednesday evening by two gunmen in front of his young son as he was putting footballs in his car after finishing a coaching session with an under-15 soccer team.