Hassan Salameh was badly wounded by gunfire in the West Bank town of Hebron, south of Jerusalem, as he tried to flee from a car in which soldiers were later said to have found an Uzi submachine gun.
"I want to be a martyr, not to be arrested by the Israelis," he was quoted as saying by a visitor to the Alia hospital, where he was taken.
Hebron, home to 100,000 Palestinians, has long been a centre of militancy, particularly since the arrival of 400 Jewish settlers in the heart of the town. The partial Israeli military withdrawal from Hebron, agreed with the Palestine Liberation Organisation, has been delayed until after the Israeli election on 29 May.
The Israeli government is extremely nervous that there will be another suicide bomb attack before the poll, benefiting the right-wing opposition, and has tightened security preventing Palestinians from leaving the West Bank and Gaza. Israeli radio said the presence of Mr Salameh in Hebron had been known for several weeks because of information given by 11 Hamas members arrested in Jerusalem.
The driver of Mr Salameh's car, who was also arrested, was later identified as Razik al-Rajoub, a relative of Jibril al-Rajoub, who heads the Palestinian Preventive Security Service in the West Bank.
Mr Salameh is said by Israel to be the deputy of Mohammed al-Deif, a member of Izzedine al-Qassim, Hamas's military wing. The Israeli government has long demanded that the PLO leader, Yasser Arafat, arrest Mr Deif, whom it believes was behind the three suicide attacks in February and March in which 63 people were killed in Israel.
Hamas, which opposes Mr Arafat's peace agreement with Israel in 1993, called on its military wing on Friday to refrain from attacks against Israel ahead of the election.
Mahmoud al-Zahhar, a Hamas spokesman, told a rally in Gaza: "We appeal and demand from you [Qassim] not to take any step in coming days before Israel's elections, so that no one can say that we are a tool serving the interests of one Zionist party over another."Reuse content