Fledgling efforts by Palestinian police officers to bring order to Gaza erupted in a raging, back-alley gunbattle Wednesday, when a Hamas militant who ran a red light in an unregistered car threw a grenade at police rather than accept a traffic ticket, police said.

A bystander died in the violence at a main intersection during morning rush hour in Gaza City (search). It underscored the difficulty police will have in taming this chaotic territory filled with armed militants, as all sides jockey for position before a possible Israeli pullout.

"There is no question that it's not an easy job," said Palestinian legislator Marwan Kanafani.

Matters were further complicated by a new Israeli military offensive launched against Gaza militants in the wake of a double- suicide bombing that killed 10 people in Israel on Sunday. Six Palestinians have been killed in the offensive.

Israeli Prime Minister Ariel Sharon said last month he was considering pulling out of Gaza as part of his "disengagement plan" to reduce friction with the Palestinians.

The announcement sparked fears of a power vacuum and spurred more violence, as Israeli forces and Palestinian militants targeted each other and Palestinian factions waged deadly power struggles.

To quash the chaos, the Palestinian Authority (search), at Egypt's prodding, adopted a new, phased security plan for Gaza that begins with restoring order to the roads and ends with a ban on carrying weapons in public.

Over the past 10 days, police have fanned out, enforcing traffic laws, pulling cars over for spot document checks and just trying to sort out the mess of Gaza's chaotic roads, where cars with handwritten, cardboard license plates drive the wrong way down one-way streets.

On Wednesday morning, a patrol of 21 police officers pulled over an unregistered car carrying three Hamas (search) militants that had run a red light, police officials said. When they tried to give the driver a ticket, he threw a grenade at them, slightly wounding 18 of the officers, police said.

The men in the car then engaged police in a gunbattle in the back alleys of Gaza City, where bursts of automatic gunfire mixed with the wail of sirens and the honking horns of gridlocked cars. One bystander was killed before the men were subdued.

Hamas official Said Sayem denied the Hamas militants attacked the police.

"The Hamas members in the car were not armed, and the Palestinian civilian who was killed in the street was hit by the gunfire from the Palestinian police," he said.

In an ongoing effort to emphasize the importance of reining in the Gaza militants, Osama El-Baz, a top adviser to Egyptian President Hosni Mubarak, met Wednesday with Palestinian leader Yasser Arafat, a Palestinian official said.

Moussa Arafat, a top security official and Arafat's cousin, said the incident in Gaza would not deter the Palestinian Authority.

"Law and order is going to be implemented," he said.

But the security plan forces police to walk a fine line in trying to bring Gaza under control without appearing to be cracking down on the more popular militants, a senior Palestinian security official said.

Palestinian militant groups, including Hamas and Islamic Jihad (search), agreed to accept the Palestinian security force's authority and not to carry weapons in public, Palestinian officials said. But whether they will actually implement this, and what police can or will do if they don't, remained an open question.

But Kanafani wondered how Palestinian police would be able to continue giving out traffic tickets and checking whether drivers have the proper insurance while Palestinians awaited the next Israeli airstrike.

If the attacks stop, "maybe we'll have a better chance," he said.

Since the start of the Israeli offensive Tuesday night, six Palestinians have been killed and 32 wounded.

Helicopters fired two missiles during raids Wednesday morning in the Rafah refugee camp on the Gaza-Egypt border, killing four people, including two unarmed teenage boys, Palestinian officials said.

The army said it fired the missiles at groups of militants who were aiming grenades, bombs and anti-tank missiles at soldiers searching for weapons smuggling tunnels in the camp. No Israeli casualties were reported.

"The extremists should know that they cannot be immune when they send terrorist groups to kill Israelis time and time again," Israeli Foreign Minister Silvan Shalom said.