KABUL, Afghanistan — Insurgents tricked an 8-year-old girl in a remote area of central Afghanistan into carrying a bomb wrapped in cloth that they detonated remotely when she was close to a police vehicle, the Afghan authorities said Sunday.

Only the girl was killed in the blast, which occurred Sunday morning in the village of Uwshi in the Char Chino District, said Fazal Ahmad Shirzad, the police chief of Oruzgan Province.

Mr. Shirzad said he believed the girl was unaware that the bag she had been given by Taliban insurgents held a bomb. Her body was “taken to a nearby security check post, and the police called her relatives,” he said.

Meanwhile, in Logar Province in southeastern Afghanistan, the death toll rose to 37 after a bombing on Saturday at a small-town hospital, said Dr. Mohammad Zaref Nayebkhail, the director of public health for the province. He said that at least 53 people had been wounded.