The rocket attack was the first since November, when a truce ended fighting across the border. This comes at a time of mounting tension and Palestinian protests.
According to Israeli police a rocket hit a road in the industrial area of Ashkelon, a few kilometers north of the Gaza Strip early on Tuesday morning. No injuries or damage were reported, and no warning sirens were sounded.
"An explosion was heard in the Ashkelon region, experts searched the area and found one rocket that had struck, damaging a road but causing no injuries," police spokesman Micky Rosenfeld said.
No Palestinian group claimed responsibility for the launch.
It is the first such rocket to be fired from the Palestinian territory, which is ruled by the Islamist Hamas, since a truce with Israel had been agreed in November.
The truce ended an eight-day Israeli military operation, during which more than a thousand rockets were fired into Israeli territory from the Gaza Strip. According to figures subsequently published by both sides, the violence claimed the lives of 177 Palestinians, about a hundred of them civilians, and six Israelis, four of whom were civilians.
Tuesday's rocket fire comes as tensions are particularly high following the death of a Palestinian prisoner in an Israeli prison.
30-year-old Arafat Jaradat died suddenly on Saturday at the Megiddo detention center in northern Israel. Prison officials blamed cardiac arrest. They denied that he had been mistreated during interrogation, but said that he had suffered injuries prior to his arrest including a hit to the stomach by a tear gas canister.
Israel's domestic intelligence agency, Shin Bet, said Jaradat – a father of two - had been arrested for his alleged involvement in a rock-throwing incident in November 2012 in which an Israeli was injured.
An autopsy that was scheduled for Sunday at Israel's national forensic institute was postponed, pending a court ruling on procedures, such as whether Jaradat's family, his attorney and the Palestinian Authority's head of forensic medicine could attend.
An Israeli military spokeswoman said hundreds of people took to the streets on Sunday in Jaradat's home village of Kfar-Sa'ir, near Hebron in the West Bank, throwing rocks at soldiers who responded by firing teargas and rubber bullets.
Both the Palestinians and the United Nations special coordinator for the Middle East peace process, Robert Serry, have called for an independent inquiry into his death.
Jaradat's death in custody fuelled support for Palestinian prisoners on hunger strike in Israeli prisons (a protester pictured above). One has refused solid food for more than 200 days.
On Monday Israeli troops shot and wounded five Palestinians during confrontations in the Bethlehem area, and a 15-year-old boy was reportedly in critical condition.
Palestinian President Mahmoud Abbas issued a statement instructing Palestinian security officials to preserve order in the West Bank, but he also blames Israel for the violence planned visit next month.
The renewed tension comes ahead of a planned visit to the region by US President Barack Obama.
rg/kms (Reuters, dpa, AP, AFP)