An Ohio man with a large knife was arrested Wednesday morning outside presidential hopeful Barack Obama's hotel in southeast Iowa, police said.

Davit Zakaryan, 24, was searched and apprehended after Obama's Secret Service agents allegedly saw him loitering outside a Fairfield Inn in Ottumwa before the Illinois senator was about to leave for a busy day of campaigning.

Police said they do not know why Zakaryan was outside the hotel with the knife, and they cautioned against making any assumptions until he is questioned further.

"This is not an earth-shattering" arrest, said Lt. Mike McDonough of the Ottumwa Police Department.

"He made no threats toward the senator."

Zakaryan was arrested after 8:30 a.m. and charged with possessing an illegal weapon and driving without a license. Police said the knife was longer than 8 inches, which exceeds the state limit. Zakaryan was being held Wednesday night at the Wapello County Jail on a $6,825 bond. He will be arraigned Thursday morning.

Tommy Vietor, a spokesman for Obama's Iowa office, said he was not familiar with the specifics of the arrest, but complimented police and Secret Service for their efforts.

McDonough said Obama's security crew had been keeping an eye on Zakaryan because they thought his car looked familiar and may have been at another of Obama's campaign stops. After Zakaryan pulled the car near the hotel, the agents asked police to question him. That's when they found the knife inside the car, McDonough said.

McDonough said the identification card Zakaryan gave them shows he's from Ohio, but they aren't sure if it's a valid ID. McDonough said he's not sure what Ohio city is listed on the card.

Obama, a Democrat, has spent much of his time campaigning in Iowa the last few months, trying to build support for the state's leadoff caucuses in January. On Wednesday, Obama made stops in Oskaloosa, Pella and Des Moines, participating in July 4 celebrations and visiting with activists.

Obama has been escorted by Secret Service since May — the earliest a candidate has ever received such protection.