Israel carried out an air strike near the Gaza residence of Palestinian Prime Minister Ismail Haniyeh of Hamas on Friday, but insisted he was not the target.
"Haniyeh's home definitely was not the target," an Israeli army spokeswoman said.
"There was an air strike on a structure used by the Hamas terrorist organisation in Shati refugee camp."
Residents said a missile hit a caravan used by Hamas men guarding a street leading to Haniyeh's home in Gaza, wounding one person.
Israeli officials have in the past publicly put Haniyeh on notice he and other Hamas political leaders could be attacked if cross-border rocket attacks continue.
Hamas on Thursday defied a call by President Mahmoud Abbas to stop firing rockets at Israel.
"Rockets will be fired as long as the Zionist aggression against our people continues," said Hamas official Sami Abu Zuhri after Abbas, meeting a European Union envoy, described such attacks as "pointless and needless".
Abu Zuhri said Abbas, who heads the Fatah movement which joined Hamas in a unity government two months ago, did not back "resistance" and had "contradicted the Palestinians' consensus".
Israel sent troops into Nablus in the occupied West Bank on Thursday and took Palestinian Education Minister Naser al-Shaer, a member of the Islamist group, into custody.
They also detained at least three Hamas legislators, Nablus's mayor and deputy mayor and other Hamas officials in neighbouring towns and villages.
Israeli Defense Minister Amir Peretz appeared to suggest the detentions could put pressure on Hamas to stop rocket attacks from Gaza. The army said seven rockets and a mortar bomb were fired at Israel during the day.
"It's better to arrest the leaders so that perhaps such a move can speed up a return to a ceasefire rather than allow the region to slide into total escalation," Peretz told Israel's Channel 2 television.
The United States expressed misgivings about the arrests but said Israel had a right to defend itself.
"The detention of elected members of the Palestinian government and legislature does raise particular concerns for us," State Department spokesman Tom Casey told reporters.
The Israeli army said 33 people were held across the West Bank. After Hamas won a parliamentary election last year, Israel seized more than 30 Hamas politicians, who are still in jail.
Hamas, the military said, was exploiting "governmental institutions to encourage and support terrorist activity".
Israeli aircraft on Thursday hit Hamas positions in Gaza City and the southern Gaza town of Khan Younis, where residents said five people were wounded.
An air strike destroyed a metal workshop which the Israeli military described as an Islamic Jihad weapons factory in the southern town of Rafah.
Javier Solana, the EU's foreign policy chief, described the Hamas-Fatah unity government as "non-functioning" in an interview with Reuters and another news agency in Jerusalem.
Hamas and other militant groups said they would consider stopping the rocket fire only if Israel first called off all its military operations in Gaza and the West Bank.
Israel has rebuffed similar demands in the past, arguing its West Bank operations prevent militant attacks.
Some 50 Palestinians have died in this month's factional fighting. Air strikes have killed at least 35 Palestinians, and militant groups said 23 of them were fighters. More than 150 rockets, one of which killed an Israeli, have been fired from Gaza over the past week.
(Additional reporting by Jeffrey Heller and Adam Entous in Jerusalem and Atef Sa'ad in Nablus)