TACLOBAN, Philippines (AFP) - There is no roof, running water or electricity at the Divine Word Hospital in the typhoon-wrecked Philippine city of Tacloban, where three men lie waiting to have their legs amputated.

Doctors, nurses and pharmacists busily rush around patients with horrific injuries, all crammed into a darkened lobby 12 metres by six.

Part of the ceiling has caved in, exposing now-useless electrical wires that dangle harmlessly towards the ground.

"At the height of the typhoon, we were the only hospital left functioning," Valentina Gamba, the director of nursing, told AFP.

"Even now, it's just us and the government hospital operational in Tacloban."

Super Typhoon Haiyan tore the roof off the hospital when it smashed into Tacloban, a once-bustling city of 220,000 people.

The storm surge brought by the most powerful typhoon ever to hit land inundated the ground-floor of the 200-bed facility, destroying the magnetic resonance imaging machine, ultrasound and X-ray, as well as the emergency room and laboratory facilities.

"We acquired the MRI for 65 million pesos (S$1.85 million) six months ago. It has not yet been fully paid for," said Gamba.

"We lost nine patients during the typhoon, when a power cut affected those who were on life support."

Reinforcements have arrived in the seven days since the typhoon, with relief doctors from the southern Philippines being joined by volunteer medics from Israel, Japan and South Korea.

The additional staffing meant they could open a surgery ward on the second floor.

"These three are scheduled for amputations," she said, pointing to two men lying on benches and a third on a gurney. All three were hooked up to intravenous drips.

One had an open fracture on his right leg, and the two others had large, open leg wounds.

About two dozen walk-in patients were also crammed into the room, including children, crying as they were given injections.

Nearby, pharmacists sorted donated medicines into small boxes for distribution to people who needed them, while a doctor injected a woman in a darkened corridor where intravenous drips were stacked and the floor was covered with used boxes.

Hospital security man Rogelio Sabugo, 39, stood guard, unarmed and wearing shorts, a camouflage jacket and slippers.

"My house was ruined and I left my wife and two kids under a table that now serves as our temporary home," he said. He reported for work as normal on Saturday, the day after the apocalyptic storm barrelled through.

Outside, an elderly Catholic nun of the Benedictine Sisters of Tutzing, which runs the hospital, directed six boys in a clean-up of the driveway, shovelling away the mud and debris that the sea had brought ashore.

"The hospital was hit with 10-foot storm surges, it is very depressing," said Sister Eloisa David.

David had worked at the hospital from 1990 to 2007, and was on the relatively untouched island of Bohol, around 150 kilometres from Tacloban, when the storm came.

When she heard about what had happened to the hospital, she rushed to help.

"There is no electricity, there is no water. We bring in water in a truck," she told AFP.

Sam Bajeo, a government doctor from Davao Regional Hospital in the country's south, wore basketball shorts, a singlet and slippers as he examined one patient.

With the situation so dire, the normal rules of hospital etiquette and division of labour have gone out of the window.

"I helped clean up the operating room upstairs, so I got wet," he said.