Israel strikes 'Hamas camp' in Gaza and will further delay Qatari funds
Hamas, the de facto ruling party in Gaza, confirmed that Nabahin was a member of its armed wing, the Izz al-Din al-Qassam Brigades.
Hamas said two of its military wing's observation posts had been hit east of Beit Hanoun.
The Israeli army said it had targeted a Hamas observation post after a soldier was lightly wounded earlier on Tuesday when a bullet struck his helmet.
An unconfirmed picture circulating on social media showed the damaged helmet allegedly worn by the soldier.
The incidents signalled a rise in tensions after weeks of relative calm thanks to an informal truce between Israel and Hamas.
An Israeli official said a transfer of cash from Qatar to Gaza via Israel as part of the truce would not occur on Wednesday because of the violence.
There had been warnings of another escalation in recent days due to Israel withholding delivery of the funds which is helping to inflict a major crisis on Gaza's hospital services.
Israeli Prime Minister Benjamin Netanyahu is campaigning for re-election on 9 April and the payments from Qatar have sparked opposition from right-wing activists and politicians.
Qatar's ambassador to Gaza had said on Monday that the $15m in cash to pay salaries of Hamas civil servants in the enclave was expected to be delivered this week, possibly Wednesday.
But an Israeli official said on condition of anonymity that Netanyahu had decided not to allow the transfer on Wednesday.
The payment would be the third of six planned tranches, totalling $90m.
Palestinians have been protesting every Friday since 30 March as part of the Great March of Return.
The protest campaign calls for an end to the 12-year Israeli blockade on Gaza and for Palestinian refugees' right of return to the lands that their families fled during the establishment of the state of Israel in 1948.
At least 251 Palestinians in Gaza have been killed and thousands injured since the demonstrations began, mostly by Israeli fire during protests but also by air and tank strikes.
Two Israeli soldiers have been killed over the same period, one by a Palestinian sniper and another during a botched Israeli special forces operation within the Gaza Strip.
Israel maintains a crippling blockade of the strip which critics say amounts to collective punishment of the impoverished enclave's two million residents.
Egypt also upholds the siege, restricting movement in and out of Gaza on its border.