An Israeli air strike in Gaza has killed two people, including a senior Palestinian militant leader, according to reports.

The second victim was Mahmoud Hanani, according to Palestinian officials. Hanani was released from an Israeli prison five years ago.

The strike was reportedly retaliation for mortar shells fired into Israel from Gaza just hours before.

Zohair al-Qaisi, secretary-general of the Popular Resistance Committees (PRC), a coalition of several Palestinian factions which oppose the more conciliatory stance of the Palestinian Authority, was apparently targeted by Israel Defense Force because his group was planning an assault on Israel, according to the Haaretz newspaper.

PRC is loyal to Hamas, which governs Gaza, but sometimes operates independently. In fact, it was PRC which originally captured celebrated Israeli soldier Gilad Shalit (who was subsequently returned to Israel in exchange for the release of many Palestinian prisoners from Israeli jails).

Al-Qaisi took over PRC last August when his predecessor, Kamal al-Nairab, was similarly killed by Israeli missiles.

According to other reports, there was also second Israeli strike upon Gaza that killed two other Palestinians, BBC said. However, details on the strike are unavailable.

BBC reported that PRC has already vowed vengeance for the latest missile attack.

PRC, which was formed in 2000 and is reportedly financed by Hezbollah, has carried out a number of bombing attacks on both civilian and military targets in Gaza. Israeli officials blamed al-Qaisi for a wave of bomb attacks in southern Israel last summer which killed eight Israelis.