More than 20 people are trapped under the rubble of a building under construction in the Philippines that collapsed on Sunday, officials said, as rescue ​efforts continued.

Five people were confirmed trapped, including two in contact with rescuers, ​and 18 more were feared under the rubble, officials said.

"We have five ⁠confirmed trapped victims, and we have a figure of 18 workers from the list ​of construction workers on duty today, but no feedback yet from their families. This ​brings the estimated number of trapped victims to 23 as of today," Maria Leah Sajili, information officer at the regional Bureau of Fire Protection, told a press briefing.

At the site of the collapsed multi-storey building ​under construction in the city of Angeles, north of the capital Manila, rescuers were seen ​clambering over a mound of concrete slabs and mangled steel, covered in green netting, searching for ‌survivors.

The ⁠number of rescued, including those in the vicinity, remained at 24, with no deaths reported, Sajili said.

Among the rescued was a 51-year-old Malaysian national who was staying in a nearby budget hotel, which was damaged when the concrete structure collapsed, Jay Pelayo, the Angeles city ​information officer, told Reuters ​in a phone ⁠interview.

He had earlier told DZBB radio that 30 to 40 people were feared trapped, based on information from a site foreman who was among ​those who escaped.

Officials said the cause of the collapse is ​under investigation, ⁠but records showed the building was intended as a nine-storey condo-hotel under the approved permit, but a 10th floor for a pool was being constructed.

Ambulances were on standby, and fire ⁠trucks had ​been deployed to assist in the rescue, Pelayo ​said, adding that moving the concrete debris was a challenge for rescuers.