Afghan insurgents launched deadly attacks in key cities Wednesday, even as the coalition continued to transfer security control to Afghan forces.

Afghan officials said a gunbattle between local forces and insurgents killed three police officers, including the district chief, and two militants in Kandahar city Wednesday.

Separately, a bomb planted on a bicycle killed at least four civilians, including a child, and wounded 10 others in Mazar-i-Sharif. The northern city and capital of Balkh province is one of seven areas where foreign forces are handing over security responsibility over to Afghan troops, in the first phase of the security transition.

Earlier Wednesday, NATO transferred control of Lashkar Gah, the capital of Afghanistan's volatile Helmand province, to the Afghans during a ceremony. Helmand Governor Gulab Mangal told VOA by phone that it was an historic day and that local security forces are “ready and happy” to take command.

The southern city is the third area to be handed over to the Afghan government after Bamiyan province and the relatively peaceful city of Mehterlam in eastern Laghman province.

The transfers are 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 leave Afghanistan by the end of 2014.

Violence has increased since March, when President Hamid Karzai announced which areas would be the first to be transferred to local forces.

Earlier on Wednesday, the Afghan Taliban denied that its leader Mullah Omar is dead, saying a text message announcing his death was a fake.

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

Rumors of Omar's death periodically arise, including in March when an Afghan news channel said he had been killed by members of Pakistan's military spy agency.

The one-eyed Afghan Taliban leader has a $10 million bounty on his head. He implemented strict Islamist rule while leading Afghanistan during the 1990s.