The Norwegian Refugee Council (NRC) has called on Israel to immediately “reverse mass evacuation orders” in Lebanon, warning they risk triggering a humanitarian catastrophe as hundreds of thousands flee their homes, Al Jazeera reports.

In an email statement sent to Al Jazeera, the rights group said it estimates about 300,000 people have already been displaced in “less than 100 hours” since Israel launched a wave of air strikes on southern Lebanon, the capital Beirut, and other parts of the country.

“Families who had barely begun rebuilding their lives are now forced to flee once again,” Maureen Philippon, country director for NRC in Lebanon, says.

“People left their homes in the middle of the night with nothing but the clothes they were wearing. Once again, civilians are paying the highest price. If implemented, the latest evacuation orders from Israel could yet produce a humanitarian crisis unlike anything we have seen in over two years.”

The NRC has warned that the number of people forced to flee could exceed 1 million if the orders are fully implemented.