The United Nations has received permission from Israel for about 100 more aid trucks to enter Gaza on Tuesday, a spokesperson for its humanitarian office said.

"We have requested and received approval for more trucks to enter today, many more than were approved yesterday," Jens Laerke, spokesperson for the U.N. humanitarian office told a Geneva press briefing.

Asked to specify how many, he said "around 100."

After an 11-week Israeli blockade, Israel cleared nine trucks of aid on Monday to enter Gaza through the Kerem Shalom crossing, although Laerke said just five of those entered Gaza.

"The next step is to collect them, and then they will be distributed through the existing system, the one that has proven itself," said Laerke, adding that those trucks contained baby food and nutritional products for children.

Malnutrition rates in Gaza have risen during the Israeli blockade and could rise exponentially if food shortages continue, a health official at the U.N. Palestinian refugee agency UNRWA said at the same briefing.

"I have data until end of April and it shows malnutrition on the rise," Akihiro Seita, UNRWA Director of Health, told a Geneva press briefing. "And then the worry is that if the current food shortage continues, it will exponentially increase, and then get beyond our control."