Supply shortages could worsen aid workers' means to provide care, MSF said.
A ceasefire went into effect at 4 a.m. local time Wednesday morning after Israel's Cabinet approved the U.S.-backed proposal to end the fighting between Israel and Hezbollah after prolonged negotiations.
The Israel Defense Forces continues its intense airstrike and ground campaigns in Gaza, particularly in the north of the devastated Palestinian territory.
Tensions also remain high between Israel and Iran after tit-for-tat long-range strikes in recent months and threats of further military action from both sides.
The Israel Defense Forces launched another airstrike in southern Lebanon on Friday after it said they identified "terrorist activity and movement of a Hezbollah portable rocket launcher."
The IDF said the "threat was thwarted in an IAF strike."
"The IDF is deployed in southern Lebanon and will actively enforce violations of the ceasefire agreement," it said in a statement.
-ABC News' Dana Savir
Israeli Prime Minister Benjamin Netanyahu has threatened an "intensive" war if Hezbollah violates the ceasefire agreement, according to an interview he did with a local reporter.
"I gave the IDF instructions," Netanyahu said, speaking to the right-wing Channel 14. "If there is a massive violation of the agreement ... we [will] operate surgically like we are doing now, and with force ... I instructed the IDF to prepare for an intensive war.”
The Israel Defense Forces said it fired at suspected terrorists Thursday. Hezbollah has not yet commented on the strike and there have been no indications rockets have been fired into Israel from the north.
"The IDF remains in southern Lebanon and acting to enforce violations of the ceasefire agreement," the IDF said in a statement.
The Lebanese Army confirmed the strikes hit within its territory, saying Israel "violated the agreement several times" on Wednesday and Thursday.
"After the ceasefire agreement was announced, the Israeli enemy violated the agreement several times, through air violations and targeting Lebanese territory with various weapons. The Army Command is following up on these violations in coordination with the relevant authorities," the Lebanese army said in a statement.
Over 2,500 children in the Gaza Strip need "urgent medical evacuation," according to the United Nations Children's Fund.
"The situation in the northern Gaza Strip is extremely difficult and tragic and is getting worse," UNICEF spokesperson Kazem Abu Khalaf said in a statement.
"Thirty percent of children in the Gaza Strip suffer from severe malnutrition," Abu Khalaf said. "Ninety-five percent of the schools that house displaced people in the Gaza Strip have been completely destroyed," he said.
