Five aircraft, two from the Malaysian Maritime Enforcement Agency (MMEA), two from the Royal Malaysian Air Force and one from the Royal Malaysian Navy, have joined the effort.
The MMEA said that it had also widening the search area to include the Malacca Strait as well as Sabah and Sarawak waters.
The 7,301-dwt Orkim Harmony (built 2009) lost communication with its owners last week and is believed to have been hijacked.
The