KABUL, Afghanistan — The Taliban took the four men to the main bazaar in a southern Afghanistan district at evening prayer on Sunday, regional government officials said, denounced them as government spies because they were carrying satellite phones, then beheaded them in front of local residents who had been summoned to watch.

Three days later, on Wednesday morning, the director of a relatively progressive radio station in eastern Afghanistan was found stabbed to death in his car. His back, stomach and chest had been slashed, and his throat slit, according to the man’s brother, who said his head had been nearly severed from his body.

The local police chief, Daulat Khan Zadran, said the victim, Sadeem Khan Bahader Zoi, had been totally beheaded. “We still don’t know the cause” of the killing, Mr. Zadran said, but the method was consistent with the Taliban.

A Taliban spokesman for eastern Afghanistan, Zabiullah Mujahid, strongly condemned Mr. Zoi’s killing and in a telephone interview denied that the Taliban had been involved. The Taliban spokesman responsible for southern Afghanistan could not be reached for comment on the beheadings there.