A Saudi Arabian diplomat has been killed in a drive-by shooting in the Pakistani city of Karachi.

Police say four gunmen on two motorcycles opened fire at a car belonging to the Saudi Arabian consulate from two sides.

Pakistan's Al Qaeda-linked Taliban have claimed responsibility for the killing.

"Until America stops chasing Al Qaeda and stops drone strikes we will keep carrying out such attacks," a spokesman said via phone from an undisclosed location.

Saudi ambassador Abdul Aziz al-Ghadeer condemned the attack, saying "no-one who carries out this kind of attack can be a Muslim".

He did not give details on the rank of the diplomat who was killed.

"The Saudi national killed was himself driving the car and was probably going to the consulate from his house," a police spokesman said.

An official from the media section of the Saudi embassy identified the man as a Saudi diplomat, while another official from the embassy earlier identified him as a security official working for the consulate in Karachi.

Pakistani police in Karachi said the man had been driving in a vehicle with diplomatic plates when two motorcycle riders opened fire at a crossroads in an upmarket neighbourhood.

"The consulate employee died of multiple bullet wounds on the spot," said Fayaaz Leghari, the police chief of southern province Sindh, of which Karachi is the capital.

"The attackers fled on the motorbikes."

Pakistani provincial home ministry official Sharfuddin Memon identified the dead man as a junior officer at the consulate.

His death comes after drive-by assailants threw two grenades at the Saudi consulate in Karachi last Wednesday.- Reuters/AFP