The Afghan Taliban has denied that its leader Mullah Omar has died, saying a text message announcing his death was a fake.

A Taliban spokesman said Wednesday the message was sent after the group's phones and website were hacked, and blamed U.S. intelligence agencies.

Omar has been reported dead before, including in March when an Afghan news channel said he had been killed by members of Pakistan's spy agency.

The one-eyed Afghan Taliban leader has a $10 million bounty on his head. He led Afghanistan during the 1990s, establishing strict Islamist rule under which girls were banned from going to school.

Also Wednesday, officials in southern Afghanistan said militants killed at least three policemen during a gunbattle in the city of Kandahar, including the district police chief.

The attack comes as Afghan forces continue to take security control of some areas from NATO troops, and international forces begin leaving the country.

U.S. forces handed over control of the relatively peaceful city of Mehterlam in eastern Laghman province during a ceremony on Tuesday.

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.

Security control of Lashgar Gah, the capital of southern Helmand province, is set to be handed over to local troops later this week.

Afghan officials said seven police officers were killed by one of their colleagues at a checkpoint outside the city Monday.

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

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.

On Sunday, Bamiyan province became the first area to be handed over to Afghan forces.