A senior Palestinian official in the Gaza Strip has died in an Israeli air strike in the town of Rafah.
Hundreds of supporters vowed to avenge the strike
Jamal Abu Samhadana founded the Popular Resistance Committees, which regularly launches home-made rockets into Israel.
Samhadana, a senior security chief in the Hamas-led government, was one of four killed in the attack on a training camp, which injured seven others.
He was one of Israel's most wanted men in Gaza, and was thought to be involved in a 2003 attack on a US convoy.
A training camp in Rafah - on the Egyptian border - was shaken by four explosions close to midnight local time (2100GMT).
It soon became clear that Samhadana was one of the four killed.
Hospital officials said despite serious injuries Samhadana's face was recognisable, according to the Associated Press news agency.
The Israeli military confirmed the strike, saying it targeted militants who were planning an attack on Israel.
Samhadana had narrowly escaped four previous assassination attempts, once being so badly injured that he lost a leg, the BBC's Alan Johnston in Gaza says.
Samhadana had become close to the Hamas movement which now controls the Palestinian government, our correspondent says.
His appointment to the interior ministry recently infuriated Israel and the Palestinian opposition faction, Fatah.
Samhadana founded his militia at the start of the latest uprising
The move was also bitterly condemned by the Palestinian Authority President, Mahmoud Abbas.
Hamas and the Popular Resistance Committees (PRC) expressed their anger over Samhadana's death.
A spokesman for the PRC vowed to "open the gates of hell" in response.
As word of Samhadana's death spread, hundreds of angry militants converged on the hospital where his body was lying.
They fired their weapons in the air and swore that they would strike back at Israel, our correspondent says.