Palestinian militants in the Gaza Strip fired two Grad rockets at southern Israel on Thursday, as cross-border tensions continued to escalate.

One of the rockets struck south of of Ashdod and the other just north of the city. It was not exactly clear where the second rocket hit, but the explosion could be heard in Yavneh, some 25 kilometers from Tel Aviv.

A few hours later a Qassam rocket fell in the city of Sderot, and a mortar fell in Sha'ar Hanegev Regional Council. There were no casualties and no damage was done in both cases.

A Grad rocket hit Ashdod and another two struck Be'er Sheva on Wednesday, as well, prompting the Israel Air Force to launch a series of attacks against militant groups and smuggling tunnels in the Gaza Strip.

Militants persisted in volleying rockets and mortar shells across the border into southern Israel amid the IAF strikes.

Approximately five mortar shells and two Qassam rockets struck Israeli territory overnight, and another rocket was fired at the Ashkelon coast on Thursday morning, after militants fired dozens of rockets and mortars into the western Negev in the days prior.

The Hamas rulers of the Gaza Strip said early Thursday that the Israeli strikes had targeted smuggling tunnels along the Gaza-Egypt border, as well as one of its training camps inside the Strip.

One of the strikes hit a power transformer, causing blackouts in the area, Gaza witnesses said. Medical workers reported no casualties.

Palestinian police in the Gaza Strip reported that another strike hit what Hamas officials called an abandoned rocket launcher in the northern part of the territory, also causing no casualties.

An Israel Defense Forces spokesperson confirmed the air operations, calling them a response to the rockets fired at southern Israel over the last few days.

The IDF said that the attack against the rocket launcher struck "a group of terrorists preparing to launch rockets at Israeli territory." 

The first rocket that hit Be'er Sheva on Wednesday hit a street in the middle of a residential area, damaging buildings including a synagogue. A piece of shrapnel penetrated a nearby third-floor apartment upon impact, lightly wounding one man. The second hit an open area in the city. A number of people were treated for shock in both incidents.

An Israel Air Force craft retaliated for the attack on Ashdod overnight on Wednesday, and struck Gaza again shortly after the second rocket hit Be'er Sheva. The Israel Defense Forces said the squad responsible for launching the rocket was hit.

Israel Police do not believe that the deadly Jerusalem bombing on Wednesday was connected to the increase in rocket fire on the south.