WRIGHT-PATTERSON AIR FORCE BASE — A security test that indicated a suspicious substance was on a United Parcel Service delivery truck at a base gate prompted mandatory repeat examinations and the brief closing of part of Ohio 444 on Wednesday morning.

The truck was subsequently cleared and admitted to the base, authorities said.

The follow-up examinations found no evidence of anything suspicious on the UPS truck and it was allowed to enter Wright-Patterson Air Force Base to complete its delivery, base spokesman Daryl Mayer said.

The UPS truck was directly behind a truck that had entered Gate 16A minutes earlier bringing an expected load of munitions, Mayer said. Base authorities speculated that sensitive monitoring equipment might have initially detected traces of a substance still in the air from the munitions truck when the UPS truck was examined.

The initial finding from the UPS truck prompted a series of re-examinations that are required by security protocols, Mayer said. The incident began at about 9:30 a.m. and was resolved about two hours later.

At the base’s request, the Ohio State Highway Patrol closed Ohio 444 to traffic between Kaufmann Avenue and Ohio 844 for about 45 minutes when traffic backed up from the entry gate.

Contact this reporter at (937) 225-2242 or jnolan@DaytonDailyNews.com.