KARACHI  - A US Federal Bureau of Investigation (FBI) agent who was arrested in Karachi for trying to board a plane while carrying ammunition was released on bail Thursday, officials said.

The agent was arrested at Karachi airport on Monday when security staff found him carrying 15 bullets for a 9mm handgun during routine checks for a flight to Islamabad.

A Karachi court approved the bail application and ordered payment of a bond worth one million rupees ($10,000), senior police officer Rao Anwar told AFP.

US officials in the port city collected him from a police station after the payment was deposited. "The FBI agent has been handed over to the US consulate in Karachi," a police spokesman said. An AFP photographer at the scene confirmed the handover.

The US citizen was also ordered to appear in court for further hearing of the case. The arrested FBI agent Jewel Cox was currently on a 4-day police remand till May 10.

, when the court approved his bail before two days of remand's completion.

Sources said the police report did not identify the FBI agent's involvement in any suspicious activity.

Cox was arrested while carrying bullets for 9-MM pistol, a magazine and spying tools including pen-camera.

The arrested FBI agent was provided special protocol in police custody and got special breakfast served from a foreign restaurant in the morning.

According to media report, FBI agent was shifted to Artillery Police Station for four days physical remand where the accused was kept in a room instead of lock-up. On the other hand, the police were facing problems in investigation because the US agent spoke in English and replied only with an answer to contact his embassy.

According to details, some gadgets recovered from the accused could not be decoded in Pakistan. Being a US citizen, extra ordinary security arrangements had been made at Artillery Police Station with media men not allowed to enter the station.

Meanwhile, sources said FIA had got important information from agent's laptop.

They said FIA crime circle and other agencies investigated the case.

The incident came at a time of relative tranquility in Washington's often-fraught relationship with Islamabad.

Ties have improved markedly since almost collapsing in 2011 amid a series of crises including the US raid in Pakistan that killed Al-Qaeda chief Osama bin Laden, which Islamabad branded a violation of sovereignty.

The fatal shooting of two men by CIA contractor Raymond Davis in Lahore in January 2011 sparked another diplomatic crisis between the two "war on terror" allies.

A Pakistani court eventually freed Davis following the payment of $2 million in blood money to the families of the dead men.