KATIF, Gaza Strip  —  Armed militants set up checkpoints in Gaza's (search) evacuated Jewish settlements for a second day Thursday, doing the job of Palestinian security officials who have been unable to rein in the chaos since Israel's withdrawal.

Dozens of gunmen from the Al Aqsa Martyrs' Brigades (search) — a militant group linked to Palestinian leader Mahmoud Abbas' ruling Fatah movement — were determined to restore order and stop fellow Palestinians from looting valuable equipment from greenhouses Israel left behind.

The gunmen's rule underscored the weakness and ineffectiveness of Abbas' Palestinian Authority (search), which has failed to impose law and order throughout Gaza. The lack of control was most apparent along the Gaza-Egypt border, where people have been crossing largely unfettered since Israel's pullout on Monday.

Abbas' inability to control the area strengthens the rival Hamas militant group just three months ahead of a parliamentary election, when Fatah and Hamas are to face off for the first time in a political playing field. The outcome of the Gaza power struggle could greatly influence voting.

Driving in a three-car convoy and protected by a dozen gunmen, Raed al-Ayde, the local Al Aqsa commander, checked in on his forces. He made a quick stop at the former Katif settlement, where 20 Al Aqsa gunmen, identifiable by their black baseball caps, had set up shop on Wednesday.

Alongside them, just 12 Palestinian police were stationed at the entrance to the former settlement. Their uniforms were shabby and incomplete, and not all of them had weapons.

Early Thursday, Taha Qassas, an Al Aqsa operative, toured the checkpoints, taking roll call, overseeing shift changes and handing out water. According to Qassas' list, 400 gunmen were to report to duty Thursday throughout the Gaza Strip.

Complicating the picture is a new plan by Abbas to disarm all the militant groups, starting with the ones close to his own Fatah movement — the Al Aqsa Martyrs' Brigades.

In the heat of the Gaza day at the demolished settlement, the two sides debated who gives the orders.

The gunmen and the Palestinian security forces drank tea and talked calmly as they sat under a makeshift gazebo made of four wooden poles and a black mesh awning they scavenged from the settlement rubble.

Behind them, dozens of greenhouses were in shambles.

"You can't be Aqsa boys and Palestinian Authority boys at the same time," Khaled Masri, a Palestinian police officer, told the gunmen. "You have to choose one or the other."

"This is how civil wars begin," said Masri. After a second of silence, the gunmen and soldiers, almost in unison, dismissed that possibility.

Part of Abbas' plan is to absorb all groups associated with the ruling Fatah party into the security forces, and some think it's possible to answer to two masters.

"When they go to work, and they are wearing military uniforms, they will take orders from their military commanders. But when they go home and the work day is over, they take their orders from us," said Hassan Qassas, Al Aqsa's leader in Khan Younis.

"As a body, the Al Aqsa Brigades will remain," he said on Wednesday.

Qassas even commended Abbas for his pledge to rid Gaza's streets of what he called "illegal" weapons, used in petty crimes rather than against Israel.

He said Al Aqsa is willing to "hide" their weapons and keep them out of sight, but the group will not give them up.