Afghan forces have taken security control of a provincial capital in eastern Afghanistan from NATO troops, the latest step in the transition process as international forces begin leaving the country.

During a ceremony in Laghman province Tuesday, U.S. forces handed control of the relatively-peaceful city of Mehterlam to Afghan troops.

The provincial capital is one of seven areas in Afghanistan to be transferred to the Afghan government this month. It is the first phase of a plan that will see all of the country's security under Afghan control in the next three years.

International combat troops are set to completely withdraw from Afghanistan by the end of 2014, and some foreign forces have already begun pulling out of the country.

On Sunday, the NATO transferred control of the northern province of Bamiyan to Afghan forces.

Violence has increased in Afghanistan since President Hamid Karzai announced the first phase of the security transition.

Security control of Lashgar Gah, the capital of the restive southern province of Helmand, is also set to be handed over to local troops this week. Afghan officials said seven police officers were killed by one of their colleagues at a checkpoint outside of Lashkar Gah Monday. The attacker later escaped with their weapons and a police vehicle.

Despite the violence, the Afghan government official who heads the transition process said Tuesday that Afghan forces were fully capable of handling security in the seven areas to be transitioned first.

Separately on Tuesday, NATO said a bomb attack killed one of its service members in eastern Afghanistan. The coalition did not give details.