(Bloomberg) -- The Philippines’ main airport will continue to have flight delays Tuesday as airlines reel from a technical glitch on New Year’s Day that stranded thousands of passengers and caused a backlog at the flag carrier that could take weeks to clear. 

Operations at the Ninoy Aquino International Airport in the capital region are expected to fully normalize Wednesday or Thursday, said Bryan Co, senior assistant general manager at the agency that manages the gateway. There will be no more cancelled flights but delays are expected, he told CNN Philippines Tuesday.

A power supply problem caused the Manila airport’s traffic management system to go offline for several hours on Sunday, which Co said disrupted holiday travel plans of more than 65,000 passengers. The Department of Transportation has launched a probe and senators are also planning an investigation.

Philippines Restores Air Traffic Control After Power Outage

Philippine Airlines Inc. will likely clear the backlog caused by the glitch “in a few weeks,” spokesperson Cielo Villaluna said in a separate CNN Philippines interview, adding that the national carrier has deployed bigger planes and additional flights to normalize operations. Cebu Air Inc. is also working on the recovery of its network, the airline said in a Facebook post Monday.

The Civil Aviation Authority of the Philippines, which runs and maintains air navigation facilities, is coordinating with airlines to ensure safety of passengers. “All procedures are in place, including for contingency, so we will be ready to respond just in case it happens again,” Edgardo Diaz, deputy director at the aviation authority said separately on state television.

The agency is prepared to answer questions from lawmakers when they conduct an inquiry into the incident, Diaz said.

PLDT Inc. Chairman Manuel Pangilinan was among those affected by the New Year’s Day delays, tweeting that he had to return to Haneda airport in Japan from a Manila-bound flight with radar and navigation facilities down in the Philippine airport. “6 hours of useless flying but inconvenience to travelers and losses to tourism and business are horrendous,” he tweeted Jan. 1. In a tweet the following day, Pangilinan said his companies are “happy to participate” in improving connectivities and power supply at the airport.

Transport Secretary Jaime Bautista on Dec. 28 said the government plans to start accepting proposals this year to develop the more than 70-year-old airport, with the terms for its privatization likely ready in the first quarter.

--With assistance from Ditas Lopez.

(Updates with comments from airport official from fifth paragraph.)

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