The collapse of two buildings killed 22 people in the northern Moroccan city of Fes, authorities said Wednesday, in the deadliest accident of its kind in the kingdom in recent years.

Sixteen others were wounded as searches for "other people who may be buried under the rubble" were ongoing, the country's official news agency MAP reported.

The Fes prosecutor's office said in a statement, there had been a family celebration in one of the buildings at the time of the collapse while the other was unoccupied.

The prosecutor's office added an investigation had been opened to "determine the real causes" of the incident.

The two adjacent structures collapsed overnight in the major northern city's Al-Moustakbal neighbourhood, in the Al-Massira area, according to MAP.

Images from the pre-dawn scene showed first responders carrying a corpse in a grey body bag to waiting emergency vehicles, as residents gathered to watch the rescue efforts.

Other workers with jackhammers and pickaxes tried to dig through the rubble, at times with the help of mechanical excavators.

Mohamed, a local resident interviewed by outlet Le 360, said the construction standards for the buildings may not have been observed when the occupants built on the plots they received there in 2007 as part of a resettlement programme.

"After 2007, everyone built as they wished," he said.

TelQuel magazine reported that the homes "were not subject to oversight", adding that some tenants may have "not respected development plans".

Deadliest in a decade

Local authorities have indicated that the toll could rise in the coming hours.

MAP said that safety officials had conducted "necessary preventative measures", including securing the surrounding area and evacuating neighbouring buildings.

The agency reported the injured were taken to Fes's University Hospital Centre.

The accident was the deadliest of its kind in a decade. 

In 2014, three buildings in the western city of Casablanca collapsed, killing 23 people.

In 2016, there were two deadly building collapses within the span of a week.

One was a home in the western city of Marrakech where two children were killed, while the other was a four-storey building that killed four people and injured two dozen more.

In February of last year, five people died in the collapse of a house in Fes's old city.

Last May in Fes, nine people died when a residential building collapsed.

The structure had been listed as at risk of collapse and its occupants had been ordered to evacuate, a local authority source told AFP at the time.