An Oregon man walked into a state office on Wednesday with a pressure cooker he claimed was a bomb and told employees he tried to blow up a sign outside the building because it was misspelled.

Leonard Burdek, a 50-year-old from Salem, Ore., arrived at the Teacher Standards and Practices Commission offices shortly after 9 a.m. Wednesday.

“He walked quite confidently into our office as though he had a mission," Vickie Chamberlain, the commission's executive director, told the Statesman Journal. "That was what alarmed me right off the bat."

Burdek allegedly placed the pressure cooker—wires sticking out of it—on the counter in front of the receptionist, informing her of his failed bomb plot. The man also allegedly complained that the instructions he downloaded to make the device also were misspelled.

The sign in the parking lot appears to be missing the letter "d," so it reads, “Teacher Standards an Practices Commission.” Chamberlain told the paper "it’s possible that someone scraped the letter off or it wore off over time." The opposite side of the two-sided sign is not misspelled.

After employees called 911, Burdek left the building with his pressure cooker. He was later arrested and charged with disorderly conduct after police determined it was not a bomb.

“It looks like he was just trying to get attention,” Salem Police Lt. Dave Okada said.

While the case appears to be little more than a prank, there's been heightened concern over the use of homemade bombs in the wake of last month's deadly Boston Marathon bombings.

Dzhokhar Tsarnaev and his brother, Tamerlan, are suspected of using a pair of homemade pressure cooker bombs to carry out the attack. Authorities say the brothers learned to make the explosives using instructions posted online.