The number of Palestinians slain in vigilante killings and other internal violence nearly quadrupled over the past four years, from 43 in 2002 to 151 so far in 2005, according to statistics presented Thursday, and one top security official said more Palestinians were killed in internal violence this year than by Israeli troops. The descent into lawlessness was hurting Palestinian leader Mahmoud Abbas politically, at a time when he was trying to beat back a tough challenge by his Islamic militant rivals. This week, a Palestinian parliament frustrated with armed gangs and corrupt police officers ordered Abbas to disband his cabinet and make crime-fighting his top priority. "The security situation is deteriorating in a very dangerous way, with no one putting a stop to it," said Hassan Khreisheh, the deputy parliament speaker. In the most recent incident, gunmen affiliated with Abbas' ruling Fatah movement killed a Gaza taxi driver Sunday. At the time, a group of drivers were blocking a junction in southern Gaza to protest rising fuel prices. The gunmen demanded the junction be cleared, then opened fire, killing 30-year-old Yasser Barakeh. Abbas promised Barakeh's family he would track down the killers, but no arrests have been made. Some security commanders have become warlords, using the men under their command for personal gain or illegal enterprises, such as weapons deals or extortion. In many cases, policemen are moonlighting as gunmen in militias. The overlap is particularly pronounced in the Al Aqsa Martyrs' Brigades, which has ties to Fatah. Abbas, meanwhile, has shied away from confronting the armed groups for fear of civil war. However, his attempt to get armed men off the streets with promises of jobs and political participation has had only limited success. Abbas' security chief, Interior Minister Nasser Yousef, argued that he couldn't fight crime without a political decision to confront the armed groups. "When Hamas keeps its military wing, then Fatah will say, we have the right to do the same," said Yousef's spokesman, Tawfiq Abu Khoussa, referring to unlawful armed gangs linked to the ruling party. "That's what makes it so difficult for the interior minister to fight chaos and implement the law," he continued. Abu Khoussa said that in 2005 more Palestinians were killed by fellow Palestinians than in fighting with Israel. He did not provide figures, but his claim was backed up by the Independent Commission for Human Rights, an independent Palestinian group. Majed Arouri, a researcher for the group, said 151 Palestinians have been slain in internal violence or as a result of reckless behavior by militants in 2005 so far. For example, the Palestinian-on-Palestinian death toll rose sharply in September when 22 Palestinians were killed when rockets exploded inadvertently at a Hamas military parade. By comparison, 140 Palestinians were killed by Israeli troops during the same period, Arouri said. Statistics about deaths during the five years of Palestinian-Israeli violence are imprecise because of several factors, including differing methods of categorization and conflicting claims of responsibility and blame for many of the deaths. Arouri said there had been a sharp increase in vigilante killings and other slayings of Palestinians by Palestinians in recent years. In 2002, there were 43 such killings, compared to 56 in 2003 and 93 in 2004, he said. The growing chaos was quickly turning into Abbas' biggest political headache - even more than the threat from Hamas that is poised to do well in January parliament elections. This week, angry legislators gave Abbas two weeks to present a new Cabinet and focus on battling crime, even ahead of negotiations with Israel. "Chaos is the most dangerous threat Mahmoud Abbas and the Palestinian Authority are facing now," said Palestinian analyst Hani al-Masri. "If the Palestinian Authority doesn't take hard steps to protect us from chaos, it will collapse."