Malaysian police have been told to step up their standards in probing elements of the disappearance of Malaysia Airlines Flight MH370, now said to have “gone down” in the southern Indian Ocean.

Prime Minister Najib Abdul Razak was addressing personnel at an event to observe the 207th annual Police Day in Kuala Lumpur this morning.

"We may not get the complete answer, apart from finding the flight data recorder and black box ...,” he said.

"But other investigations need to be carried out for the sake of MH370 victims, families and friends who need answers and full explanations. This is the 21st century-type police work challenge.”

Najib said the police can now augment the armed forces and experts from 26 nations who had worked together with Malaysia on the world's biggest hunt in the last 18 days.

The plane went missing less than an hour after taking off from Kuala Lumpur International Airport on March 8.

"Even though the search and rescue operations and tracing the lost aircraft has been tasked to Malaysia's armed forces and those from other countries, the investigation into the cause for the tragedy needs a diligent police force," he said, addressing some 2,000 police chiefs and officers, mostly from Klang valley.

After a week of searching in the South China sea, the focus has turned to areas west of Peninsular Malaysia after it was learned through radar and satellite data that MH370 turned west.

'Foul play not ruled out'

IGP Khalid Abu Bakar had said the police have not ruled out foul play, including pilot or co-pilot suicide. He is due to brief reporters later at PWTC on the latest findings.

This is Khalid's ( left ) first police day celebration as IGP. In his speech, he outlined the police plans to fight crime, after citing that crime rates fell 4.3 percent in 2013 compared to 2012.

These include Ops Cantas, Special Crime Task Force (Stafoc) and a Special Tactical Intelligence Narcotic Group (Sting). An anti-bribery campaign was also launched this year.

Meanwhile, at a closed-door ceremony following the Police Day Celebrations, Home Minister Ahmad Zahid Hamidi gave out 104 national warrior (Pingat Jasa Pahlawan Negara) medals to the police officers who served during the first and second national war against communism.

The first was from 1948 to 1960 and the second, from 1964 to 1990. For some, it is a posthumous award. It is being handed out in stages, with 146,888 recipients so far.

About 3,463 police officers died and many more suffered or were crippled by the war against communism, Ahmad Zahid was quoted as saying in his speech.

Only the Bernama news agency was allowed in to cover the event.