Malaysian Prime Minister Najib Razak has spoken out on the persistent haze currently shrouding Malaysia, Singapore, Indonesia and even the Philippines, stressing that the Indonesian government needs to take action against parties causing the crisis.

Speaking to reporters on Sunday (Oct 4) in Milan, Italy before boarding a plane bound for home after a three-day visit, Datuk Seri Najib said only Indonesia could take action against the irresponsible companies, as this would prove whether the cause of the haze was down to open forest burning or weather conditions, reported Bernama.

"They (plantation companies) are operating there, we want Indonesia to take action. Summoning them is one thing, but proving they conducted such acts is another matter," Bernama quoted him as saying.

"Only Indonesia alone can gather evidence and convict the companies concerned.

"It should also be determined if the cause of the fires are deliberate or due to weather conditions."

Mr Najib said Malaysia, Indonesia and Singapore had to cooperate closely to find a solution to the problem, reported Bernama. One way of doing this was to come up with more effective measures that "will take into consideration the agreement signed by the three countries to combat haze".

" Malaysia, Singapore and Indonesia are still working on interpreting the agreement into a suitable form of action to ensure the situation does not recur," he said.

Bernama said Mr Najib added that the haze was also affecting Malaysia's economy.