Ireland's health ministry was the target of an attempted cyber attack, the Irish government said on Sunday, days after a similar attack struck the country's health service.

"The National Cyber Security Center (NCSC) became aware on Thursday of an attempted cyber attack on the Department of Health," the government said in a statement.

It explained "some functions" of the department's IT system had been suspended "as a precautionary measure."

"This attempted attack remains under investigation, however there are indications that this was a ransomware attack similar to that which has affected the HSE," it added.

The cyber attack on the Health Service Executive (HSE), which its chief Paul Reid described to public broadcaster RTE as an "international criminal operation," forced the Irish health service to shut down its computer systems.

Non-urgent appointments were cancelled but the country's COVID-19 vaccination campaign was not impacted.

Attacks using ransomware, a form of malicious software that encrypts a victim's files, have been on the rise in recent years. 

After the cyber attacker has control of the computer system, they then demand a ransom from the victim to restore access to the data.