Published Wednesday, 21 November 2012
David Black died in an ambush on the M1 on Thursday 1 November. (© PA)
The pair, aged 34 and 42, were detained in Coalisland by detectives from the Serious Crime branch.
Mr Black, a prison officer from Cookstown, was ambushed by gunmen as he travelled to work at Maghaberry Prison earlier this month.
A dark blue Toyota Camry with Dublin registered number plates pulled up alongside the 52-year-old's black Audi A4 on the M1.
Shots were fired and Mr Black's car immediately veered off the road and into a deep drainage ditch. He was the 30th prison officer to be murdered in Northern Ireland since 1974.
The men have been taken to Antrim Serious Crime Suite for questioning.