The security detail was escorting a convoy of the Oil and Gas Development Company Limited (OGDCL) on a coastal highway travelling to Karachi from the port town of Gawadar.

The area has been sealed off and a search operation for the assailants had been launched.

It was the second major attack in Pakistan in 24 hours.

In a separate incident six soldiers, including one officer, were killed in an IED attack by terrorists on security forces convoy near Razmak in North Wazirstan district.

Two explosions targeted military patrols along the Afghan border near Razmak, North Wazirstan, ISPR said.