MANILA - National Economic and Development Authority (NEDA) officials on Thursday downplayed concerns that the extension of martial law in Mindanao might hurt the economy.

Socioeconomic Planning Secretary Ernesto Pernia said the declaration's effect is "neutral at most."

Undersecretary Rosemarie Edillon, meanwhile, said that while it may be difficult to project the impact of martial law in Mindanao, which has been in effect since May, it appears that it has "really no discernible impact" in terms of inflation, tourism, construction and shipping.

"There was even a slight decline (in inflation)," she said, comparing the periods January to May, before the martial law declaration, and June to November.

In Luzon and Visayas, inflation levels remained the same, the official said.

Edillon also cited improved investment indicators in Mindanao compared to Luzon and Visayas.

"In fact, there was a slight uptick for the second period, which is after the martial law declaration in Mindanao, mainly because of Davao," Edillon said.

"But again, this also goes to show that the rest of investors actually were able to isolate the Marawi crisis from the martial law implementation, and that did not affect their decisions," she added.

In the fourth quarter Business Expectations Survey and the Consumer Expectations Survey, the martial law declaration was not listed among issues that were bothering respondent consumers and businessmen, she said.

In a joint session Wednesday, Congress approved the extension of martial law in Mindanao until December 2018.

After 4 hours of deliberations, a total of 240 legislators voted to extend military rule anew until the end of 2018 while 27 rejected the proposal.

President Rodrigo Duterte had sought a fresh extension citing persistent security threats, including extremists and communist rebels.

It is the second extension of Duterte's initial 60-day declaration in May, when firefights erupted in Marawi City. Congress first granted an extension in July, with the period supposed to lapse Dec. 31 this year. Government declared the end of hostilities in October.