The Defence Forces is conducting a major exercise in the Dublin area on Wednesday.
The exercise will involve over 500 Defence Forces personnel, including the elite Army Ranger Wing, working with members of An Garda Síochána.
The Defence Forces says members of the public can expect to see military vehicles, armoured vehicles, helicopters and armed personnel involved in the exercise.
It says it hopes to keep any disruption to a minimum.
But it says the exercise is necessary "to ensure that the Defence Forces are fully prepared when called upon."
The Defence Forces will be posting updates to its Twitter account.