The sun sets over the northern Gaza Strip as seen from the Israeli border August 9, 2014.
Israeli gunboats on Sunday opened fire at fishermen off the coasts of Gaza city in a breach of the five-day truce, which will end on Monday midnight.
Palestinian sources said the Israeli gunboats opened fire at the ships without previous warning, but no damage or injuries were reported, MENA news agency reported.
Israel has imposed wide restrictions on the Gaza fishing zone.
Since Israel launched its Operationa Protective Edge July 8, the lives of at least 1,938 Palestinians, mostly civilians, have perished, according to Palestinian health officials.
At least 64 soldiers and three civilians were also killed in the conflict, according to the Israeli military and police.
On Thursday, Hamas and Israel agreed to a five-day truce after several failed ceasefire agreements.