A website of the US Treasury's Bureau of Engraving and Printing (BEP) was suspended Tuesday after it was hacked, a BEP spokeswoman said.
"The hosting company used by the Bureau of Engraving and Printing had an intrusion and as a result of that intrusion, numerous websites (BEP and non-BEP) were affected," Claudia Dickens told AFP.
The Treasury Government Security Operations Center was made aware of the problem on Monday and subsequently notified BEP, she added.
She said the BEP website and four internet addresses (URLs) pointing to it -- BEP.gov, BEP.treas.gov, Moneyfactory.gov and Moneyfactory.com -- have been suspended until further notice.
As of late Tuesday, the websites were still inaccessible.
The hacking incidents were first reported by a blog of an AVG software vendor official, who said the attacking sites were traced to Ukraine.
Explore further: Facebook dressed down over 'real names' policy