Irish government websites were hit by a sustained cyberattack overnight Friday, according to local media reports.
The office confirmed the entire Irish government network experienced what is known as a Distributed Denial of Service (DDoS) attack, in which hackers overwhelm a site by flooding it with phony traffic, according to the Times.
The websites of the HSE, the Department of Justice, the Courts Service, the Department of Defence and the Central Statistics Office were all down on Friday morning.
The attack began overnight and was resolved by the afternoon. No group has yet taken credit for the attack.
"As with all DDoS attacks, it is not possible to identify the exact source of the attack," a representative for the Office of Public Expenditure and Reform said.
Earlier this week, the Irish National Lottery experienced a similar attack that knocked it offline for two hours.