GAZA CITY (Ma'an) -- Israeli military air strikes injured five people across the Gaza Strip overnight on Thursday.

Medics told Ma'an that three people were seriously injured in an air strike on the northern city of Beit Lahiya.

An Israeli army spokeswoman said the military targeted the launch site of a rocket in northern Gaza around 10.00 p.m. Thursday.

Shortly after, air strikes hit central and southern Gaza, and witnesses told Ma'an that two Palestinians from the Al-Tuffah neighborhood of Gaza City had been injured.

The Israeli army spokeswoman said that forces targeted "three tunnels in central Gaza Strip and a terror activity site, as well as a terror activity site in the southern Gaza Strip. Direct hits were confirmed."

The attacks were "a response to four rockets fired into Israel in the past week," she said.

A rocket which landed on Thursday in the Hevel Lakhish Regional Council, near northern Gaza, did not cause any injuries, but two people were treated for shock, Israeli army radio reported.

Early Thursday morning, two air raids targeted military sites including one belonging to Hamas' Al-Qassam Brigades, a Ma'an correspondent said. There were no reports of injury or damage following the attacks.

The four airstrikes on Thursday come amid recent escalations along the border as Israeli warplanes struck two targets Tuesday in the northern and southern parts of the coastal enclave.

The past month has seen an increase in rockets and other projectiles fired at Israel from Gaza after several months of calm following a flare-up in April when an anti-tank missile hit an Israeli school bus, killing a teenager.

Israel responded to that attack with a series of air strikes that killed at least 19 Palestinians in the deadliest violence since Israel's devastating 22-day assault on Gaza in December 2008-January 2009.

Israel has imposed a blockade on the Gaza Strip since Hamas took control of the enclave in 2007. Rights agencies have condemned the blockade as a form of collective punishment.