Wreckage of car in which Hassan Madhoun and Fawzi Abu Kara were travelling in Gaza

Two top Palestinian militant leaders have been killed in an Israeli airstrike in the northern Gaza Strip.

Authorities say Hassan Madhoun, a senior member of the al-Aqsa Martyrs Brigades, and top Hamas militant Fawzi Abu Kara were killed Tuesday, when an Israeli missile hit their car near the Jabalya refugee camp. The Palestinian Authority says at least nine bystanders were wounded.

A short while after the attack, spokesmen for Hamas and al-Aqsa Martyrs Brigades vowed to retaliate.

Israel says the al-Aqsa militant was wanted in connection with a 2004 bombing that killed 10 people in the Israeli port of Ashdod.

Israel has carried out numerous strikes in Gaza since a Palestinian suicide bomber killed five Israelis in central Israel October 26.