At least nine people, seven of them schoolgirls, have been injured by an Israeli air attack in the southern Gaza Strip, sources tell Al Jazeera.
The raid on Thursday in Khan Yunis also injured a police officer, the AFP news agency reported, quoting witnesses and medics.
Israel seemed to be targeting a Palestinian fighter on a motorcycle, witnesses told Al Jazeera.
The raid came several hours after Israeli jets attacked what witnesses said was a metal foundry in Rafah, a town near Gaza's border with Egypt.
"An aerial attack took place against a site used to manufacture weapons in an area of the city of Rafah following the firing of a rocket into southern Israel in [Wednesday] evening," an Israeli army spokesman told AFP.
The military later said that a second missile was fired into southern Israel from Gaza early on Thursday, but that no damage or injuries were caused.
Al Jazeera's Hoda Abdel-Hamid, reporting from Gaza City, said: "These kinds of attacks cause a lot of tension amongst the people, and there is apprehension that these tit-for-tat attacks could escalate and a full on war could resume."
Ehud Olmert, the Israeli prime minister, has called for a security cabinet meeting to discuss expanding the military response to Gaza rocket fire, sources tell Al Jazeera.
The al-Aqsa Martyrs Brigades, the military arm of the Fatah faction led by Mahmoud Abbas, the Palestinian president, claimed responsibility for Wednesday night's rocket attack from Gaza - the first since Palestinian factions declared their own ceasefire with Israel.
The rocket landed at the kibbutz or agricultural commune of Reim, in the southern Israeli Eshkol region, an Israeli military spokesman said on Thursday.
The attack came after Israeli jets carried out raids on tunnels under the Gaza-Egypt border earlier on Wednesday - the first tunnel bombing since it halted its 22-day offensive on January 18.
The Israeli army said in a statement on Wednesday that its air force had hit a number of "Hamas smuggling tunnels" in retaliation for a roadside bomb attack by Palestinians on a vehicle patrol the previous day.
Gaza fighters had killed an Israeli soldier and wounded three others in the attack along a border fence.
Shortly after the bomb attack on Tuesday, Israeli aircraft killed one Palestinian on a motorcycle in an air attack.
Hamas confirmed that one of its members was injured in the attack in the town of Khan Yunis.