A truck reportedly bore a flag for the Islamic State of Iraq and Syria in Michigan over the weekend.
On Sunday morning, the flag was just a short distance away from the United States Army Reserve Center in Southfield, WWJ reported.
Reserve center officials told the CBS affiliate that an anti-terrorism drill involved the flag.
The truck was away from the reserve center for a short period of time, officials told the television station, and said they were sorry for the confusion.
The news arrives as the US Marine Corps on Sunday urged ‘vigilance’ after a group claiming to be Islamic State hackers published what they said were the names and addresses of 100 military personnel and urged supporters to kill them.
The warning came after a group calling itself the Islamic State Hacking Division posted information about members of the air force, army and navy, including photos and ranks, on the Internet, according to monitoring group SITE Intelligence.
The US Marine Corps said it was visiting all affected staff, and urged caution online.
‘Vigilance and force protection considerations remain a priority for commanders and their personnel,’ US Marine Corps Lieutenant Colonel John Caldwell said in a statement, adding that the threat remained ‘unverified’.
‘It is recommended Marines and family members check their online/social footprint, ensuring privacy settings are adjusted to limit the amount of available personal information.’
The Pentagon regularly tells service members to be careful about what they post online.
The self-proclaimed IS Hacking Division claimed it took the information from government servers, databases and emails and called on its followers to mount attacks.
A defense source, however, told The New York Times most of the information was in fact available in public records and did not appear to have been hacked from government servers.
The IS Hacking Division said the 100 military staff had targeted the Islamic State group in Iraq, Syria and Yemen.
‘With the huge amount of data we have from various different servers and databases, we have decided to leak 100 addresses so that our brothers residing in America can deal with you,’ the group wrote.
Read more: dailymail.co.uk