Two Palestinians were killed on Saturday when an Israeli warplane struck with a missile their motorcycle in the town of Jabalia in northern Gaza Strip, medics and witnesses said.

Sources put the initial death toll at one, but another critically injured later died of his wounds he sustained from the fragments of the Israeli warplane missile, medics said.

Ashraf al-Qedra, spokesman for the Hamas-run Ministry of Health, confirmed that the death toll in the Israeli airstrike had risen to two, adding that a 5-year-old boy was in moderate conditions.

Medical sources at Kamal Odwan Hospital in northern Gaza Strip said the boy was coincidentally in the street when the attack took place.

According to witnesses, the two Palestinians were riding on a motorcycle driving in Mas'oud Street in the town, and a missile fired from an Israeli warplane hit them and burned their motorcycle.

Meanwhile, reports from Israel said the two killed were " militants" and members of the al-Qaida affiliated Jihad organization. An Israeli army spokesman said in a statement that the two world Jihad militants were targeted as they were behind carrying out attacks on Israel.

The Israeli airstrike on the motorcycle was a response to earlier rockets fired from the Gaza Strip on southern Israel.

A radical Salafi Islamic militant group claimed responsibility of firing the rockets, in which Israel said that one of the fired rockets on southern Israel wounded at least one Israeli citizen.

Meanwhile, an Israeli F16 warplane struck by a missile a training post that belongs to Islamic Hamas movement al-Qassam Brigades in Zeitoon neighborhood in southern Gaza City, witnesses and security sources said.

Medical sources said that one person was critically wounded in the second airstrike on southern Gaza city.

Overnight, Israeli war jets carried out two successive airstrikes on central Gaza Strip and on Gaza city. No injuries were reported after the two strikes targeted an empty land and a militants' training post.