Police in Daegu are searching for two suspects in an arson attack on a private English institute which the self-proclaimed anti-American activists apparently mistook for a U.S. government facility.

Police said the fire appeared to have been started by improvised explosives on Monday morning.

A cleaning worker, surnamed Lee, called the police after she heard an explosion and found smoke with fliers scattered in front of the institute on the third floor of a nine-story building in the city.

Police said they found pieces of broken bottles, burnt papers and fluorescent lights at the scene.

“I found some liquid which seemed to be oil on the floor. The hallway was filled with smoke when I went there after I heard the alarm bell,” Lee told the police.

“Someone seems to have thrown improvised explosives made of 120-milliliter bottles with inflammable substances inside,” a police official said.

The fliers found at the scene read, “The United States which has committed hate crimes against our people for over 100 years is now trying to provoke war. You Americans will not go back alive.” The arsonists claimed to be “a committee of anti-America and anti-fascism.”

“The suspects might have confused the school with the U.S. cultural center because of their similar names. They have nothing to do with each other,” a police official said.

Police said the organization was not officially known nor was there evidence of terrorism.

Police launched a manhunt on Tuesday, disclosing images of the suspects captured on surveillance cameras.

By Kim Young-won (wone0102@heraldcorp.com)