A security guard shot and killed an Afghan diplomat inside the Afghan consulate in the Pakistani city of Karachi on Monday, officials said.

Mohammad Zaki Abdu —the consulate's third secretary — died of his wounds shortly after the shooting, a spokesman for the Afghan consulate in Karachi, Haris Khan, said.

"We were working at our office when we heard gunshots," he said. "Everybody was running in panic when I got out."

The guard, identified only as an Afghan national named Rahatullah, was taken into custody, said police official Azad Khan.

Both officials said the motive behind the killing was not yet known. The Afghan embassy in Islamabad said it was awaiting further details.

In Pakistan, which has long been a hotbed of Islamic militancy, foreign missions are afforded extra security and also frequently hire their own private guards.

Rahatullah was Abdu's personal bodyguard, and it wasn't clear whether the Afghan consulate had hired him officially, said Khan, the police official.