Flight operations at the Kerteh Airport here were once again disrupted by the worsening haze since Sunday.

The situation has caused the postponement of 24 helicopter flights a day to exchange about 400 offshore oil and gas company crew in the affected district.

Petronas' East Coast Region Communications and Media Relations manager, Zamri Mohamad said eight flights a day using Malindo Air and Firefly, involving 560 passengers were affected.

"Operations at the airport was affected after visibility deteriorated to below 800 metres at 4pm, on Sunday and we were forced to close the airport for all flights on Sunday and Monday. Tuesday, the airport returned to normal operations when visibility was restored to over 3,000 metres," he told Bernama here today.

However, at 10.30am yesterday (Wednesday), the airport was closed again until today after visibility declined to below 800 metres. Early this morning, visibility dropped to 400 metres and at 4pm visibility was 700 metres which is still unsafe for flight operations. We are monitoring the situation from time to time," he said.