Islamic State (ISIS/ISIL) jihadists have for months incited a push against the soccer World Cup venues, most recently calling for lone-wolf attacks in a series of posters published as Russia kickstarts the world-renowned competition on Thursday.

The SITE Intelligence Group, which tracks jihadi activity online, has been documenting ISIS threats against the Russia-based World Cup for months now, with the group releasing menacing videos and posters.

On Wednesday, SITE revealed that “an Islamic State (IS)-linked group called on supporters to carry out lone-wolf attacks in a poster displaying a map of World Cup stadiums in Russia.”

Citing various posters documented by SITE, Daily Mail notes:

One of the terror group’s mocked-up images shows flames engulfing a stadium and nearby facilities at the Fisht Olympic Stadium in the World Cup host city of Sochi, southern Russia. Another calls for lone-wolf jihadists to ‘kill them all’ with the phrase written in French along with a picture of a knife slicing through a tournament logo against the backdrop of another Russian stadium. A third shows an armed militant with the caption ‘the terror will begin’ and a fourth uses a clip of the 2013 Boston Marathon bombing to call for a lone-wolf attack at football’s showpiece contest, according to the respected SITE Intelligence Group which monitors terror activity.

The ISIS call for attacks comes as the World Cup gets started on Thursday with host Russia taking on Saudi Arabia in Moscow.

On Thursday, SITE noted, “As the 2018 FIFA World Cup begins in Russia, Islamic State (IS)-linked group and supporters are continuing their push for lone-wolf attacks during the event, such as one showing FC Barcelona star Lionel Messi as a prisoner.”

In May, ISIS fanatics threatened to behead Argentine skipper Messi and Portugal captain Cristiano Ronaldo in posters.

“The two superstars were shown in a mocked-up image pinned down on the pitch in a packed stadium with knife-wielding jihadists hacking at their necks. Above the picture, released on Telegram by a pro-ISIS group, a chilling caption warned ‘the ground will be filled with your blood,'” Daily Mail points out.

Tens of thousands are expected to attend the 2018 FIFA World Cup, scheduled to be played in 11 cities in Russia from Thursday until July 15.

This year, the World Cup coincides with the holy Muslim month of Ramadan, when jihadists believe it to be heroic and exceptionally rewarded by God to die a martyr.

Thousands of Russians have traveled to the Middle East to engage in jihad on behalf of ISIS and other terrorist groups.

ISIS also targeted the 2016 Summer Olympics in Brazil, but the jihadists were unable to carry out an attack.