The New York Times reports:

In a further strike against the authorities in war-torn southern Afghanistan, the mayor of Kandahar was killed in his office on Wednesday when a suicide bomber detonated explosives hidden in his turban, officials said.

The killing heightened concerns that the tenuous security gains in the violent south are unraveling despite months of intensified fighting by NATO and Afghan forces.

The mayor, Ghulam Haider Hamidi, was killed in his office in central Kandahar, and one other person was injured, according to Zalmay Ayoubi, an official spokesman. The Taliban took responsibility for the attack, news agencies reported.

He was the second senior official killed this month after the leader of the Kandahar provincial council, Ahmed Wali Karzai, a half brother of President Hamid Karzai, was assassinated in his compound by a close associate on July 12. Mr. Hamidi, the mayor, had been mentioned as a possible successor to Mr. Karzai as factions jostle to replace him, news reports said.

Mr. Hamidi was close to Ahmed Wali, but many Kandahar residents described him as distant because he had spent many years in the United States.

Mr. Hamidi had launched a contentious campaign to destroy illegal homes in northern Kandahar city. The campaign was strongly resisted by the people who lived there, many of whom had been there for years. A day earlier, there had been a protest and the mayor agreed to meet with the protesters on Wednesday.

The bomber entered the mayor’ s compound with the protesters’ delegation, said Mr. Ayoubi, a spokesman for the Kandahar provincial governor, Toorylai Wesa.