Some 500 soldiers in the Zaitun unit have voluntarily extended the period of their military service in order to take part in Seoul's reconstruction efforts in Iraq.

The Army said Monday the soldiers, due to be discharged by February, have extended their military service period by three months to serve in Iraq.

Meanwhile, some 50 soldiers from the Zaitun unit have renounced their intent to be deployed to the Middle Eastern country.

An Army spokesman said the troops decided not to extend their tour of duty and withdrew from the Zaitun unit in order to continue their study after discharge by the end of next March.

The spokesman said the withdrawal of the soldiers will not affect the unit's mission, as the missing number will be replaced by new forces.

The 3600-strong Zaitun unit is scheduled to be deployed in the northern Kurdish region of Irbil beginning next month.