GAZA CITY, Gaza Strip (AP) – Palestinian authorities carried out their first executions since 2002 on Sunday, killing four convicted murderers in a campaign meant to halt a growing wave of lawlessness but which drew swift condemnation from human rights groups.

The executions reflected the tough challenge that Palestinian leader Mahmoud Abbas faces as he tries to impose law and order in the Palestinian areas. Abbas has made public order a top priority, but his forces have been severely weakened by internal rivalries, a lack of resources and years of fighting with Israel.

Despite Abbas’ efforts to revamp his security forces, militant groups and armed gangs continue to operate with virtual impunity, often clashing with rival factions or police.

In a fresh challenge to Abbas, two Islamic militant groups responsible for dozens of suicide bombings threatened Sunday to pull out of a four-month-old cease-fire, accusing Israel of violating the truce.

“It looks like Israel will continue in this aggression and we cannot accept that anymore,” said Mohammed al-Hindi, an Islamic Jihad leader. Al-Hindi said the groups would meet in two days to make a final decision.

The truce has brought a drop in violence, although sporadic fighting has persisted. Abbas met with the militants in Gaza last week in a bid to shore up the truce after several days of violence that included a deadly Palestinian rocket attack and Israeli arrest raids in the West Bank.

Sunday’s executions appeared to be an attempt to deter criminals and send a message to the public without directly confronting the militants. None of the executed men was believed to be affiliated with any of the major militant groups. Their crimes date to the mid-1990s.

“There is a new policy of enforcing the law, to face and fight the chaos and lawlessness in the Palestinian territories,” Interior Ministry spokesman Tawfiq Abu Khoussa said.

Abu Khoussa said Abbas signed the execution orders Saturday. Three of the men were hanged, and the fourth was shot by firing squad, in line with the sentences handed down at their trials.

There was no advance notice of the pre-dawn executions, which had been approved by Islamic authorities.

The executions follow a new wave of internal violence in the Palestinian areas. Gunmen have clashed with Palestinian security forces in Gaza at least three times in recent days.

Even after the executions, the unrest continued in the bustling West Bank town of Ramallah, where a feud between two families escalated from a fistfight into a shootout. While no one was injured by gunfire, the officials said the shooting caused public panic.