Vanuatu's capital was without water on Wednesday, a day after reservoirs were destroyed by a violent magnitude 7.3 earthquake that wrought havoc on the South Pacific island nation, killing at least 14 people and injuring hundreds, with the figure expected to rise.

Frantic rescue efforts that began at the scene of flattened buildings after the quake hit early Tuesday afternoon continued 30 hours later, with dozens working in dust and heat with little water to seek those yelling for help inside. A few more survivors were extracted from the rubble of downtown buildings in Port Vila, also the country's largest city, while others remained trapped and some were found dead.

A near-total telecommunications collapse meant people struggled to confirm their relatives' safety. Some providers began to reestablish phone service but connections were patchy.

Internet service had not been restored because the submarine cable supplying it was damaged, the operator said.

The earthquake hit at a depth of 57 kilometers (35 miles) and was centered 30 kilometers (19 miles) west of the capital of Vanuatu, a group of 80 islands home to about 330,000 people. A tsunami warning was called off less than two hours after the quake, but dozens of large aftershocks continued to rattle the country.

Of the casualties, four deaths were registered at the main hospital, six in a landslide and four in a collapsed building, a government notice said — but the figure had not been updated in more than 15 hours. More than 200 injured people were treated at Vila Central Hospital.

The Asia-Pacific head of the International Federation of Red Cross’ Katie Greenwood, speaking to The Associated Press from Fiji, said it was not clear how many people were still missing or killed.

“We have anecdotal information coming from people at the search and rescue site that are fairly confident that unfortunately those numbers will rise,” she said.

The capital’s main medical facility, Vila Central Hospital, was badly damaged and patients were moved to a military camp. Clement Chipokolo, Vanuatu country director at the prominent Christian relief agency World Vision said healthcare services, already strained before the quake, were overwhelmed.

While power was out in swathes of Port Vila, the biggest fear among aid agencies was the lack of water. Two large reservoirs serving the capital were totally decimated, the National Disaster Management Office said.

A resident, Milroy Cainton, said people were joining large queues to buy water in stores, but could only purchase two or four bottles at a time. “People are not really concerned about electricity, they're just concerned about water,” he said.

UNICEF was recording a rise in diarrhea cases among children, a sign that they had begun to drink tainted water, said Chief of the Vanuatu Field Office, Eric Durpaire.

Some people remain trapped under the rubble

At least 10 buildings sustained major damage, many in a busy downtown area full of lunchtime shoppers when the quake hit. An unknown number of people were trapped inside, and Cainton, the resident, said rescuers had been forced to target their efforts to where they believed people could be saved.

Michael Thompson, who runs a tourism business in Vanuatu, was among the rescuers and posted a video on Facebook of the frenzied rescue efforts and dust-covered survivors on gurneys along with pleas for people to bring tools and water to the site.

A building housing a number of diplomatic missions in Port Vila — including those of the United States, Britain, France and New Zealand — was destroyed, with a section of the building cleaving off and flattening the first floor. Windows were buckled and walls crumbled.

The U.S. State Department said its embassy staff were safe, but the building was no longer functional. The office opened in July as part of a push by the U.S. to expand its Pacific presence to counter China’s influence in the region.

New Zealand’s foreign ministry said officials have accounted for all embassy staff. Australia’s foreign ministry said its workers were safe.

Damage to the seaport and airport is likely to hamper aid efforts and economic recovery in a country dependent on agricultural exports and tourism. The airport was closed to commercial flights for a further 72 hours from Wednesday.

But the runway was deemed operational for humanitarian flights by French engineers who arrived by helicopter and military craft from Australia and New Zealand were due to begin arriving Wednesday night. They carry search and rescue personnel and equipment, as well as relief supplies.

Dan McGarry, a journalist living in Vanuatu, said there had been a “massive landslide” at the international shipping terminal. The government said the main wharf was closed.

Landslides have cut off a number of villages and Greenwood of the Red Cross said communications had not been established yet with some coastal areas near the center of the quake. It remained to be seen whether the destroyed downtown of Port Vila was “just the tip of an iceberg or whether that’s kind of the iceberg itself,” she said.

Vanuatu’s position on a subduction zone — where the Indo-Australian tectonic plate moves beneath the Pacific Plate — means earthquakes of greater than magnitude 6 are not uncommon, and the country’s buildings are intended to withstand quake damage.