Displaced children help to push start the families van at a temporary displacement camp near the Lebanon port in Beirut, Lebanon on Friday.

The Israeli offensive in Lebanon has trapped children there in a “relentless cycle of bombardment and displacement,” the UN’s children’s agency (UNICEF) warned Friday, disrupting access to education for hundreds of thousands of students.

About 20% of the population has been displaced, many for the second, third or even fourth time since March 2, the agency added. More than 367,000 of them are school-age children and they face disruption to their education.

There is “no safe space” for people to try and shelter in Lebanon, the UNICEF country representative there, Marcoluigi Corsi, added on Friday.

Another UN official cited Israeli strikes near makeshift shelters where displaced people were huddled close together. The attack in central Beirut “close to several collective shelters hosting displaced (people),” said Karolina Lindholm Billing, a representative for the UN’s refugee agency in Lebanon.

One aid worker warned the intensity and geographic spread of Israeli strikes and hostilities has created an “unpredictable” and “high-risk” environment for humanitarians trying to offer relief to displaced people in Lebanon.

“With hundreds of thousands of people moving, often multiple times, needs are increasing rapidly and in different locations, making it challenging for humanitarian actors to keep pace with both the scale and fluidity of the crisis,” Hovig Atamian, the assistant country director for programs at the NGO, CARE International, in Beirut, told CNN in a statement Wednesday.