Poliovirus has been detected in wastewater in multiple locations of the Gaza Strip, including two major cities in the region, the World Health Organization (WHO), Gaza health and Israeli officials confirmed on Sunday.

Among the locations where the poliovirus has been found in wastewater are Deir al-Balah in central Gaza and Khan Younis in southern Gaza, two major cities where the majority of people in the war-torn region currently reside, the officials said.

WHO officials said that while they have received no reports of people contracting polio symptoms in Gaza, an investigation is underway to identify how the virus has spread. WHO said it is working with UNICEF and the U.N. Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) to investigate and establish "prompt vaccination campaigns."

Polio is a highly infectious viral disease that largely affects children under 5 years of age, according to WHO's website. Since 1988, poliovirus cases worldwide have decreased by 99%, according to WHO.

The Israel Defense Forces announced Sunday that it will vaccinate all soldiers operating in Gaza to prevent the spread of poliovirus.

The IDF also said is is working with international organizations to provide polio vaccines for people in Gaza.

Dr. Tedros Adhanom Ghebreyesus, the director-general of WHO, sounded the alarm in a statement on Friday, saying, "The decimation of the health system, lack of security, access obstruction, constant population displacement, shortages of medical supplies, poor quality of water and weakened sanitation are increasing the risk of vaccine-preventable diseases, including polio."

Ghebreyesus added, "This poses a risk for children and creates the perfect environment for diseases like polio to spread."

-ABC News' Victoria Beaulé

Israeli Prime Minister Benjamin Netanyahu is expected to meet with President Joe Biden in Washington on Tuesday, Netanyahu's office said in a statement Sunday.

The meeting between the two leaders is scheduled to occur at noon on Tuesday, Netanyahu's office said.

Netanyahu's flight to Washington is scheduled to leave Israel on Monday morning, the prime minister's office said.

The meeting between Biden and Netanyahu will come ahead of the Israeli prime minister's July 24 address to a joint session of Congress.

The two governments had tentatively scheduled a meeting between Biden, who is recovering from COVID, and Netanyahu on Monday.

However, a Biden administration official on Sunday disputed that a date and time have been set for the meeting with Netanyahu, and that an exact date and time are still dependent on when the president tests negative for COVID and returns to Washington, D.C. Biden has been self-isolating in Rehoboth, Delaware.-ABC News' Victoria Beaulé and Justin Ryan Gomez

Multiple people were killed and others have been injured in an Israeli strike on oil storage facilities in the port of Hodeidah in Yemen, according to the Houthis who said the attack will "only increase the resolve [...] of the Yemeni people."

The Houthis accused Israel of an attack that "targeted civilian facilities, oil tanks and the electricity station in Hodeidah, with the aim of doubling people’s suffering and pressuring Yemen to stop supporting Gaza."

Israel said its attack came in response to over 200 projectiles that the Houthis have launched toward Israel, saying they targeted the port as as the main supply route for weapons transfers with Iran.

-ABC News' Ahmed Bader, Dana Savir and Bruno Nota

Israel has officially taken responsibility for airstrikes that hit Hodeidah, Yemen, Saturday saying it is in retaliation for the "hundreds of attacks carried out against" Israel in the last few months.

A strike reportedly hit the port city of Hodeidah, on the country's western coast, hitting oil storage tanks near the port, according to Al Masirah TV, a media outlet affiliated with the Houthis, and Yemeni national news agency Saba news.

The airstrike comes after the Houthis took responsibility for a drone that flew into Tel Aviv undetected on Friday, killing one person and injuring 10 others.

-ABC News' Dana Savir, Bruno Nota and Victoria Beaule

The Committee to Protect Journalists released a statement calling on Israeli Prime Minister Benjamin Netanyahu to release journalists held without charge and allow free, unimpeded access to Gaza ahead of his planned trip to the U.S.

“From the start of the war, Israel has continuously denied independent access to the media as Palestinian journalists struggle to survive. The loss of local journalists, an almost total ban on media from outside Gaza leaves a vacuum for propaganda, mis and disinformation. Claims and counterclaims remain extraordinarily difficult to verify independently. Facts are easily evaded and truth withers. No credible democracy engages in what is, in effect, a growing censorship regime," Jodie Ginsburg, the CEO of CPJ, said in a statement Wednesday.

More than 100 journalists have been killed in Gaza since Oct. 7 and others have been arrested, often without charge, according to the CPJ.

"Journalists, like the thousands of civilians in Gaza killed, arrested or displaced continue to pay an astonishing toll," Ginsburg said.

"An unprecedented number of journalists and media workers have been arrested, often without charge. They have been mistreated and tortured. The number of journalists reporting in Gaza is dwindling, and those who remain are doing so in treacherous conditions, but they cannot do so alone," Ginsburg said.

-ABC News' Guy Davies