(CNN) War-ravaged Yemen is teetering on the brink of a third cholera epidemic, the World Health Organization warned Friday.

"We've had two major waves of cholera epidemics in recent years, and unfortunately the trend data that we've seen in the last days to weeks suggests that we may be on the cusp of the third major wave of cholera epidemics in Yemen," Dr. Peter Salama, WHO deputy director-general of emergency preparedness and response, told a UN briefing in Geneva, Switzerland.

Yemen may become -- or already be -- the "poster child" for the overlap of disease outbreaks and war as the nation struggles with cholera and diphtheria, Salama said. Many Yemenis are also already weakened by malnutrition.

More than 1.1 million suspected cholera cases have been recorded in Yemen since April 2017, according to the latest WHO figures , with more than 2,300 associated deaths.

The warning of another epidemic came a day after airstrikes in Hodeidah -- which has been under assault by a Saudi-led international coalition fighting Houthi rebels -- hit a busy fish market and the entrance to the country's largest hospital, Al-Thawra.

Al Thawra Hospital in #Hudaydah is the largest in the country, last year it saw over 600 000 patients and averages about 50 000 consultations a month. WHO has invested the most in this hospital, in terms of support funds than any other hospital. #Yemen #NotATarget pic.twitter.com/h6qU2pQPEH — WHO Yemen (@WHOYemen) August 2, 2018

It remained unclear Friday how many people lost their lives in the attack.

WHO, which provides funding to the hospital, said Thursday that at least 14 people were killed and 30 injured in the attack, with those numbers expected to rise. Aid agency CARE International said Friday that at least 20 people had been killed and at least 50 injured.

The Houthi-aligned Saba News Agency said that at least 52 civilians had been killed in a series of airstrikes in the city, citing the director of the provincial health office, Abdul Rahman al-Jarallah.

'Huge amount of fear'

The damage to Al-Thawra Hospital is a further blow to a country whose health infrastructure has been severely damaged by three years of conflict.

The hospital, Yemen's largest, received at least 600,000 patients last year, WHO said. It averages around 50,000 consultations a month and is a major center for cholera treatment.

Salama said WHO staff had been in the hospital at the time helping to prepare for a mass cholera vaccination program.

CARE told CNN the airstrikes had had a big impact on residents.

"First and foremost, these attacks have created a huge amount of fear in the local community. The fish market is always busy, and to hit it at 6 p.m. when it is crowded has made people very fearful," Jolien Veldwijk, CARE's assistant country director in Yemen, told CNN.

"Water and sanitation infrastructure has also been badly damaged and cholera in Hodeidah is now spreading. Cholera cases in Hodeidah governorate recently rose by almost a third," Veldwijk said.

"The situation in Hodeidah is terrible. Anyone with any money will now have left, shops are closed and it is those with no money who are left behind and who are extremely vulnerable."

Call for peace talks

The UN's special envoy for Yemen, Martin Griffiths, told a UN Security Council briefing on the country Thursday that he planned to invite the warring parties to Geneva on September 6 for a round of peace talks, two years after the last round stalled.

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"It is time long past for us, together, to call for an early resumption of the political process, two years since the last round in Kuwait," he said.

The Saudi-led coalition, which includes the United Arab Emirates, has been in a virtual stalemate with the Houthis since an offensive began in March 2015. The Houthis control parts of northern Yemen, while the coalition-backed government controls much of the south.

Hodeidah, held by Houthi rebels, is an entry point for 70% of foreign humanitarian aid into Yemen, according to the United Nations. It also provides the rebels with critical access to the Red Sea.