MANILA - (UPDATE 3) Transport authorities on Sunday put on hold all flights in and out of the Ninoy Aquino International Airport until Monday morning because of safety concerns following Taal Volcano's ash explosion.

The Civil Aviation Authority of the Philippines (CAAP) said the NAIA shut down will be in effect up to 8 a.m. Monday. The shut down can be extended depending on Taal volcano's activity, it added.

CAAP it would also advise Clark International Airport "to shut down airport operations for everyone’s safety."

The agency said that it received information from the Japan Volcanic Advisory that Taal's ash cloud could reach Clark. But as of 9 p.m. Sunday, Clark said all flights there remain operational.

NAIA's shut down follows the raising of the alert level 4 over Taal volcano, which means that a hazardous eruption could happen within hours or days.

CAAP Director General Jim Sydiongco said they canceled NAIA operations as ashfall is dangerous for aircraft.

"Once naka pasok sa makina ng eroplano, pwede ito maka sira, mag flame out or mamatay. Ang volcanic ash ay hindi nakikita sa radar ng eroplano," Sydiongco said.

(Once it enters the plane's engine, it can cause damage, a flame out or stalling. Volcanic ash can't be detected by the aircraft's radar.)

Ash clouds can reach heights of up to 55,000 feet and do not have moisture thus, weather radars do not detect it and it is harder to see it at night, CAAP said.

The Manila International Airport Authority (MIAA) has advised airline passengers not to proceed to the airport and instead coordinate with their respective airlines for flight updates.

"We are calling on the airlines and the passengers to, before proceeding to the airport, to please coordinate with the airlines because they are the ones who are also going to make the decision to cancel, or you know, reschedule their flights," MIAA General Manager Ed Monreal said in an interview with ANC.

Monreal said NAIA runways and ramps are currently covered with volcanic ash. As of posting, a total of 169 flights have been canceled and 3 diverted.

Philippine Airlines said the following arriving PAL flights have been diverted to Clark:

• PR 721 London - Manila
• PR 421 Haneda - Manila
• PR 331 Xiamen - Manila

All flights originally scheduled to depart from Manila between 7 p.m. and 11 p.m. have been declared canceled, PAL said.

"Please standby for more information. We shall keep you posted," the airline advised its clients.

PAL said the following flights on Sunday Jan. 12 have been canceled:

INTERNATIONAL FLIGHTS

• PR 100 Manila - Honolulu
• PR 101 Honolulu - Manila
• PR 104 Manila - San Francisco
• PR 105 San Francisco - Manila
• PR 110 Manila - Guam
• PR 116 Manila - Vancouver
• PR 117 Vancouver - Manila
• PR 114 Manila - San Francisco
• PR 115 San Francisco - Manila
• PR 102 Manila - Los Angeles
• PR 103 Los Angeles - Manila
• PR 126 Manila - JFK New York
• PR 469 Incheon - Manila
• PR 419 Pusan - Manila
• PR 737 Bangkok - Manila
• PR 307 Hong Kong - Manila
• PR 310 Manila - Hong Kong
• PR 311 Hong Kong - Manila
• PR 312 Manila - Hong Kong
• PR 424 Manila - Haneda
• PR 509 Manila - Singapore
• PR 512 Singapore - Manila
• PR 732 Manila - Bangkok
• PR 360 Manila - Peking
• PR 595 Manila - Hanoi
• PR 537 Manila - Denpasar
• PR 733 Bangkok - Manila
• PR 529 Manila - Kuala Lumpur
• PR 535 Manila - Jakarta
• PR 895 Taipei - Manila

DOMESTIC FLIGHTS

• PR 2136 Bacolod - Manila
• PR 2137 Manila - Bacolod
• PR 2138 Bacolod - Manila
• PR 2818 Davao - Manila
• PR 2823 Manila - Davao
• PR 2824 Davao - Manila
• PR 2788 Puerto Princesa - Manila
• PR 2529 Manila - Cagayan de Oro
• PR 2530 Cagayan de Oro - Manila
• PR 2146 Iloilo - Manila
• PR 2825 Manila - Davao
• PR 2808 Davao - Manila
• PR 2198 Manila - Laoag
• PR 2199 Laoag - Manila
• PR 2988Tacloban - Manila
• PR 2819 Manila - Davao
• PR 2820 Davao - Manila
• PR 2147 Manila - Iloilo
• PR 2148 Iloilo - Manila
• PR 2860 Cebu - Manila
• PR 2863 Manila - Cebu
• PR 2864 Cebu - Manila
• PR 2880 Cebu - Manila

Cebu Pacific also said it has canceled flights arriving to and departing from NAIA from 7 p.m. until 11 p.m. Jan. 12.

"Passengers booked on these canceled flights will receive a notification through the contact details they provided upon booking," Cebu Pacific said.

Affected passengers may rebook flights within 30 days without penalties, refund tickets in full, or store the value of the ticket in a Travel Fund for future use, the airline said.

It also advised passengers to check for the real-time status of Cebu Pacific and Cebgo flights through its website.

AirAsia meanwhile also announced that several of its flights have been canceled due to Taal's volcanic activity.

AirAsia advised clients traveling over the next few to check their flight status on the airline's website.

Clark airport meanwhile said the following flights have been canceled on Sunday:

• Air Asia Z2 909 CRK - CEB
• Air Asia Z2 931 CRK - ILO
• Emirates EK 338 CRK - DXB
• Philippine Airlines PR 490 CRK - ICN
• China Eastern MU 5046 CRK - PVG
• AirSWIFT T6 208 CRK - ENI

The following Clark flights have also been canceled for January 13:

• China Eastern Airlines MU 5045 PVG - CRK
• China Eastern Airlines MU 5046 CRK - PVG
• Xiamen Air MF 8697 JJN - CRK
• Xiamen Air MF 8698 CRK - JJN
• Philippine Airlines PR 490 CRK - ICN
• AirSWIFT T6 208 CRK-ENI

Taal volcano spewed a giant ash column into the air Sunday afternoon, prompting the state seismology bureau to raise alert level 4 over the volcanic island and the evacuation of residents living near it.