Story highlights The agent was released after paying about $10,000 in bail

When arrested, he had bullets, small knives and a wrench

U.S., Pakistan working to resolve the issue, State Department spokeswoman says

An FBI agent who was arrested in Pakistan this week after allegedly trying to board a flight with ammunition and knives has been released on bail, police in Pakistan said Thursday.

FBI agent Joel Cox was released after paying about $10,000 bail in the southern Pakistani city of Karachi, senior police Officer Rao Anwar said.

Cox was arrested Monday while trying to board a domestic flight between Karachi and Islamabad. He had 15 9mm bullets, three small knives and a wrench, according to police.

The agent was visiting Pakistan as part of an assignment to train local police, a U.S. law enforcement official said. Employees for the FBI and other U.S. agencies are allowed to carry weapons in Pakistan when authorized.

Cox is scheduled to appear in court Saturday to face anti-terrorism charges, which restrict unauthorized weapons and ammunition on commercial flights.

State Department spokeswoman Jen Psaki said the United States is working with Pakistani authorities to resolve this issue.

"This individual detained is an employee of the FBI who was on a temporary duty assignment to provide routine assistance to the legal attaché at the U.S. mission. But we are coordinating closely to resolve this manner with authorities and we are hopeful in that regard," Psaki said Wednesday.

U.S. officials hope this incident is more easily resolved than the 2011 case of a CIA contractor who was arrested and charged with killing two men. Raymond Davis said that he believed they were trying to rob him.

The case inflamed local anti-American sentiment and soured relations until the United States agreed to compensate the families of the two men. Davis was then freed.