The four boardings took place over the period 2-5 June 2019, as Ballarat conducted a routine patrol in the Arabian Sea in support of the Combined Maritime Forces.
The drug seizures included a large quantity of hashish and illegal narcotics weighing a combined total of 5.8 tonnes, or a haul similar in size to five family-sized motor vehicles.
The suspicious vessels, known as dhows, were believed to be engaging in illegal activity when HMAS Ballarat conducted the boardings under the authority of the Combined Task Force 150.
Commanding Officer, HMAS Ballarat, Commander Paul Johnson said the routine boardings were essential to achieving maritime security in the region.
"Our goal is to disrupt the sources of funding for terrorism and deny the narcotics trade in the Middle East. In support of the Combined Maritime Forces, we aggressively pursued a number of vessels, which had shown signs of smuggling illegal narcotics," CMDR Johnson said.
The recent hauls now brings the total number of seizures by HMAS Ballarat to 14 during her nine-month deployment to the region since October 2018.
CMDR Johnson added, "The team have been working hard to track, intercept and board these vessels in some difficult conditions."
HMAS Ballarat is a long-range frigate capable of air defence, surface and undersea warfare, surveillance, reconnaissance and interdiction. Ballarat's combat capabilities have been significantly improved under the Anti-Ship Missile Defence upgrade program, which provided an enhanced sensor and weapons systems capability.
Operation MANITOU is the Australian government's contribution to support international efforts to promote maritime security, stability and prosperity in the Middle East.
An enhanced security environment ensures Australia's safe and open access to the region while fostering trade and commerce and a rules based global order.