An Israeli security official says the transfer of aid into the territory is halted “until further notice” after a Hamas ceasefire violation.

The fragile ceasefire in Gaza faced its first major test Sunday as Israel stopped the transfer of aid and launched a wave of strikes, after it said its soldier came under fire from Hamas.

Hamas and Israel accuse each other of violations, as hospital sources in Gaza say death toll reaches 44 and IDF says two soldiers killed.

Israel on Sunday struck targets in southern Gaza after saying its troops came under fire from Hamas militants, in the first major test of a U.S.-brokered ceasefire meant to halt more than two years of war.

Israel has accused Hamas of attacking Israeli forces in southern Gaza with the military carrying out airstrikes in the city of Rafah, the first major test of the US-brokered ceasefire.

Hamas and Israel accuse each other of violating the peace deal, while hospital sources in Gaza say 44 people have been killed.

The fighting is the gravest test yet to the Gaza ceasefire and is dimming hopes that the U.S.-mediated truce would lead to a lasting peace.

The Israeli Defense Forces said it struck “dozens” of targets in Gaza, about one week after the ceasefire went into effect.