Iranian media report that the website of Iran’s Central Bank has been the target of a cyber-attack that’s thrown all of its systems offline.

ILNA reported on Tuesday morning that the Central Bank website is currently inaccessible and, according to experts, all signs point to a cyber-attack on the Central Bank website.

So far, the bank has not officially confirmed the attack, but last week the head of Iran’s Central Bank, Mahmoud Bahmani, reported that in just one day, the bank’s site was targeted by about 250,000 attempted cyber-attacks.

In recent months, Iranian government websites have been affected by extensive cyber-attacks. In April, the Ministry of Oil’s computer systems were the target of an attack by the computer malware Viper. The ministry stressed that none of its sensitive data was compromised in the attack.

ILNA’s report says there is now great concern for the security of financial data at the country’s banking and monetary policy-making institutions.

Flame and Sutxnet are two other computer viruses that have affected Iranian computer systems in recent years. Unconfirmed reports indicate that the United States and Israel have been collaborating on malware specifically to target Iranian systems and hamper the country’s nuclear activities.