Medecins Sans Frontieres say the ongoing war in Yemen and related import restrictions are taking a heavy toll on the country's medical system.

Key points: Ongoing war, import restrictions result in cutbacks in lifesaving treatment for over 4,400 patients with kidney failure

Ongoing war, import restrictions result in cutbacks in lifesaving treatment for over 4,400 patients with kidney failure Most of the 28 functioning dialysis centres in Yemen lack supplies, causing interruptions in treatment

Most of the 28 functioning dialysis centres in Yemen lack supplies, causing interruptions in treatment A man died waiting for emergency treatment

MSF said they have provided medications and supplies to treat 660 dialysis patients over a six-month period.

The support had reached four dialysis centres in most urgent need, but they said most of the 28 functioning dialysis centres in Yemen lacked supplies, which was causing interruptions in treatment.

Malak Shaher, a spokesperson for MSF, has called on international organisations to support Yemen's dialysis centres, where more than 4,400 people are treated with kidney failure.

"And this number is the last number the Ministry of Health has provided for us. So the number could be even greater now," she said, describing the situation as "critical".

Patient being treated at dialysis center in Al-Jumhori hospital in Sanaa ( Supplied by Malak Shaher/MSF )

"MSF decided last year to intervene and start supporting those centres with medical supplies," Ms Shaher said.

"But unfortunately the needs are great... The dialysis centres, they lack medical supplies.

"So the main problem here is that now they lack the financial ability to buy those supplies and then conduct the services and provide dialysis services for the people."

Ministry of Health unable to afford dialysis sessions

Ms Shaher said the war had displaced more than 2.5 million people and among those were people living with kidney failure.

"They need at least three dialysis sessions a week to stay alive and if they don't get those dialysis sessions they will have side effects that might lead to death," she said.

"And so the situation now in Yemen is because those people, most of them are poor, and they cannot afford having dialysis sessions at private centres, the only available centres are the Ministry of Health dialysis centres.

"And so for this reason the Ministry of Health, because they don't have the financial capacity, they have reduced the dialysis sessions from three sessions a week to only two."

Dialysis center in Al-Jumhori hospital in Sanaa ( Supplied by Malak Shaher/MSF )

Ms Shaher said recently a patient waiting for treatment had died. The man, she said, was in critical condition and in need of an emergency dialysis session.

"But unfortunately because the centre was full of patients at the time he passed away," she said.

Ms Shaher said the health system had been collapsing since last year when the war first started in March last year.

"With everyday the hospitals are facing more and more difficultly, it's not only the medical supplies, it's also the fuel that's keeping the hospital running, because the public electricity is not on all the time," she said.

"And so the health system has lost the financial capacity to pay for the staff, to pay for the medical supplies, to pay for the fuel, to pay for other services and so day by day the health system in Yemen is deteriorating to the worst."