Armed thieves launched a daring daylight attack on an international art festival in the Dutch city of Maastricht on Tuesday, smashing their way into a jewelry display case with a sledgehammer.

Police said they had captured two of the four suspects and were looking for the others following a heist that forced panicked tourists to flee the European Fine Art Fair (TEFAF) in the southern city.

During the theft, the suspects were wearing flat hats, glasses, and coats and threatening people with what seemed to be firearms before fleeing. According to a statement by Limburg police, no one was injured and the robbers "took possession of property."

"The police investigation, which started immediately after the robbery, led to two arrests... The police investigation is continuing in full swing. The focus is on tracing the suspects."

According to Dutch media, the burglars targeted a display case containing diamond jewelry and other goods from London jewelers Symbolic and Chase.

TEFAF is one of Europe's largest art fairs, attracting tens of thousands of people each year.

A TEFAF spokesperson emailed AFP saying, "The fair’s security teams worked quickly to disarm an offender and Dutch police were on site within minutes. Nobody was injured during the incident," adding that "robust procedures" were in place in the event of a security breach.

Social media videos showed the four men amid pandemonium at the art fair. While burglar alarms shrieked, one smashed his way into a jewelry box with a sledgehammer, striking what looked to be bulletproof glass at least 12 times.

Two of the males brandished what seemed to be weapons toward a bystander, who attempted to interfere with a huge glass vase full of flowers before retreating.

The guy with the hammer ultimately blasted through the glass, reaching in to pick up something and place it in a bag.

The men then raced passed an elderly man who had been sitting nearby on a bench during the commotion.

According to Dutch broadcaster NOS, a visitor, Jos Stassen, said  "Normally it is very quiet ... serene. But now I suddenly heard a lot of noise and I turn around and suddenly saw those men," adding that "one started beating and the others kept people away, scared everyone. I also saw a weapon. It went very fast and it lasted a very short time but I'm still shaking a little bit."

The fair had been running for 30 years and was resuming this year after a hiatus caused by the Covid outbreak.

TEFAF exhibits hundreds of pieces, including a one-million-euro 17th-century drawing by a Dutch Old Master. It is not the first time crooks have attacked the fair.

In 2011, a London jeweler's ring and diamond necklace valued at $1.2 million at the time were stolen at the show.