The National Security Council is meeting this afternoon to review Ireland's security arrangements following the Brussels attacks.
The council includes the Garda Commissioner, the Chief of Staff of the Defence Forces, and the heads of four government departments.
It's understood that such meetings are often held in the wake of international terrorist incidents.
The Taoiseach and other ministers will be briefed on the meeting's findings later this afternoon.
It is still believed that no Irish people have been killed or injured in the Brussels attacks.
The Department of Foreign Affairs has upgraded its security warning to 'exercise extreme caution' - which is a level below advising against non-essential travel.
It urges Irish people to follow the instructions of local authorities.
Anyone with concerns for family or friends in Brussels can phone the Department of Foreign Affairs on 01 408-0-200.
Anyone with concerns for family & friends #Brussels can contact the Consular Division @dfatirl on +353 1 418 0200 or https://t.co/DoG7rwmjS3
— IrishForeignMinistry (@dfatirl) March 22, 2016
The attacks follow the arrest in Brussels on Friday of the key suspect in the Paris attacks.
With the city on high alert, Susan Keogh has been speaking to Security and Defence Analyst Declan Power about how something like this can happen:
