The armed wing of Hamas has threatened to attack officials from the Palestinian Authority if the movement's besieged leader, Sheikh Ahmed Yassin, or any of its militants are harmed.
"Ezzedine al-Qassam Brigades warn the Authority and the heads of the security services, especially the mad dog Ghazi al-Jabali, against any attack on the mujahedin leader Ahmed Yassin or our fighters," the group said in a statement.
Ghazi al-Jabali is head of Gaza's police.
The threat comes after a Hamas died earlier today of wounds suffered in clashes with Palestinian police after Yassin was put under house arrest.
He was shot in the back in confrontations with police outside the Sheikh Ahmed Yassin's house last night.
The house arrest order was issued as part of efforts by the Palestinian Authority to rein in militants.
Palestinian security men had surrounded the sheikh's home last night but at one stage retreated down the street when around 3,000 Hamas supporters, some masked and armed, of his Islamic group flooded the area.
Palestinian police said later that they were in control, the crowd was dispersing and Sheikh Yassin remained under house arrest in Gaza City.
A Palestinian security official denied the man had died from their gunfire. "Hamas demonstrators initiated the fire," the Palestinian official said.
Israel and the United States had demanded Palestinian President Mr Yasser Arafat act against militants following suicide attacks in Israel.