"Gaza has been under a severe blockade for the past 16 years with high levels of poverty, with dependence on UN agencies, including UNRWA, which is the UN agency for Palestine refugees," Touma said. "So, any tightening of the blockade is going to make things that are very, very bad, far, far worse, including for civilians, among them many women and children."
Earlier on Monday, Israeli Defense Minister Yoav Gallant ordered a complete blockade of the Gaza strip, including of food, gas and electricity supplies. Israeli Energy Minister Israel Katz said he had ordered an immediate stoppage of the water supply to the Palestinian enclave.
Touma pointed out that during the 16-year blockade of Gaza, Palestinians living there could not leave.
"It is very, very hard for them to go in and out. They need permits that they're given only for humanitarian reasons and very few just to go to work," Touma added. "Now with more people fleeing their homes and with the intensifying violence, we're fearing that the humanitarian needs, that the crisis will get far worse and that we are going to be on the verge of a humanitarian catastrophe in Gaza."
Levels of poverty in Gaza, said Touma, are at above 60%, while unemployment rates among young people is one of the highest in the world.
"The dependency on food, for example, one point million people get food assistance from the UN, From UNRWA, the agency I work with, a lot of people go to our schools," she said. "In general, we had a very bad humanitarian crisis in Gaza due to the blockades, due to the several rounds of conflict. So the humanitarian needs have already been bad."
On Saturday, Hamas launched surprise large-scale attacks against Israel from the Gaza strip, prompting Israel to invoke Article 40 of its Basic Law for the country to enter a state of war. The Israeli and Palestinian authorities have so far reported hundreds of dead and thousands of injured as a result of the escalation in fighting.