The PSNI are launching a major security operation against dissident republicans over the coming days, a senior officer has announced.
The move to increase police checkpoints and patrols follows Monday's car bomb attack in Londonderry.
The blast was the latest in a series of attacks by dissident groups this year.
The police have appealed to the public for patience while the operation gets underway.
At the October meeting of the policing board, PSNI Deputy Chief Constable Judith Gillespie said that the public may face disruption as a result of the operations.
"Over the coming days you will see an increase in police activity across Northern Ireland as we continue our efforts to prevent serious harm and keep our communities safe," Mrs Gillespie told members of the board in Belfast.
She said that on occasion police activity may "delay or disrupt people going about their legitimate business".
However, she said the force would seek to minimise the impact of their activities on ordinary people and asked the public for understanding.
BBC NI Home Affairs Correspondent Vincent Kearney said dissident republicans have carried out 36 attacks so far this year.
He said that this was the highest annual total since dissident groups started their campaigns of violence.
The threat level posed by dissidents in Northern Ireland has been classed as severe for the last 18 months.
On Monday, two police officers were slightly injured when the 200lb car bomb detonated near a hotel and bank in Derry.
The blast caused substantial damage and traffic was severely disrupted for days.