As millions of men leave their families behind once they reach the Polish border to return to Ukraine and fight in the war, a cardinal has warned on the risk women and children refugees face on being trafficked by opportunists.

Rome's Synod of Bishops Secretary General Cardinal Mario Grech raised the alarm on human traffickers possibly taking advantage of Ukrainian women and children refugees, Vatican News reported. Grech made the warning during a 4-day visit to two of Poland's refugee centers under the Diocese of Warsaw. He urged governments to protect women and children as they flee Ukraine to nearby nations under the European Union.

"Ukrainian women and children must be 'protected' from human traffickers when they arrive in our countries from Ukraine," Grech said during the visit.

On Sunday's Angelus, Pope Francis repeated his appeal to Russia to end the war, which has intensified in its fourth week. The pontiff reminded that Ukrainian women and children are left vulnerable since men have to separate from time to fight the war. He urged that they be protected from society's "vultures."

"Let us think of these women and children who in time, without work, separated from their husbands, will be sought out by the 'vultures' of society. Please, let us protect them," Pope Francis said.

These calls from the Vatican coincided with the statements released by UNICEF and the International Organization for Migration. Both organizations called for the protection of women and children from possible exploitation.

In an appeal posted on its website, UNICEF particularly called out for the protection of Ukraine's 7.5 million children. UNICEF pointed out that Russia's invasion has added to the profound and lasting harm children were inflicted with from the past eight years of conflict in Ukraine. Children are deeply wounded and traumatized by the violence surrounding them, on top of many of them being killed in the war.

"By 15 March, more than 1.5 million children had fled Ukraine as war continues to ravage the country as families desperately seek safety and protection. Children fleeing war in Ukraine are at heightened risk of human trafficking and exploitation. Meanwhile, civilian infrastructure like water and sanitation facilities have been hit, leaving millions without access to safe water," UNICEF said.

UNICEF Regional Director for Europe and Central Asia Afshan Khan highlighted that the massive displacement has significantly spiked the human trafficking crisis along with acute child protection.

"Displaced children are extremely vulnerable to being separated from their families, exploited, and trafficked. They need governments in the region to step up and put measures in place to keep them safe," Kain stressed.

On the other hand, the IOM expressed concern that the number of Ukrainian refugees have reached 3 million, which included 162,000 nationals from third-world countries. IOM pointed out the resulting deteriorating humanitarian condition this large-scale movement means, which involves an increased threat to personal safety and heightened risk of exploitation.

"While cases of human trafficking are less likely to be identified in the immediate aftermath of mass displacement, initial reports from within and outside of Ukraine indicate the potential for traffickers to exploit the vulnerabilities of those fleeing the war. Instances of sexual violence have already been reported and among the individuals promising onward transportation or services, there have been indications of potential exploitation," IOM said.

The agency reported that their data show 6.48 million people are internally displaced in Ukraine based on a March 9-16 study they conducted. The study showed that 13.5% of those newly displaced have previously experienced displacement in the years 2014-2015. The elderly, the disabled, pregnant and breastfeeding women, and those with chronic illness comprise a majority of those displaced. But more than half or 53% of those internally displaced are women who need financial resources, medicines, and health services.

The United Nations High Commission on Refugees reported that Moldova is currently pressured to sustain the influx of 300,000 people in their small country. Less than half of these refugees or 110,000 were reported on staying in Moldova while the rest move to other areas in Europe that could better accommodate them. Romania is already extending assistance to Moldova to relocate the refugees in their territory.

The small town of Medyka in Poland has similarly welcomed a disproportionate number of 1.8 million refugees. The town's mayor, 64-year-old Marek Iwasieczko, stressed the need for financial assistance to sustain the need for food, accommodations, and basic hygiene.

This has prompted the UNHCR to warn on the rising needs in Ukraine and neighboring countries that have sheltered the refugees. UNHCR has called on Russia to end its hostilities.