A Gaza security source said Israeli warplanes had carried out several strikes on Hamas sites.
They said the strikes caused severe damage to the sites and some damage to citizens' homes, but did not report any injuries.
Israeli fire services in the south of the country reported 60 fires caused by balloons on Tuesday, and 24 on Wednesday, without recording any casualties.
Hamas and Israel have fought three wars since 2008.
Despite a truce last year backed by the UN, Egypt and Qatar, the two sides clash sporadically with rockets, mortar fire or incendiary balloons.
The Gaza Strip has a population of two million, more than half of whom live in poverty, according to the World Bank.
Palestinian analysts say fire from Gaza often aims to pressure Israel to give the green light for the transfer of Qatari financial aid into the strip.