The Palestinian security forces will stand tough against armed groups, their spokesman said Monday, a day after the most violent internal clash in Gaza in nearly a decade. "The Palestinian Authority is determined to implement law and order and will not allow anyone to be above the law and to gamble with the future and national interests of our people," said Interior Ministry spokesman Tawfiq Abu Khoussa. Special Report: Gaza Upheaval >> At least three Palestinians were killed in fierce clashes between Palestinian Authority security forces and Hamas gunmen that erupted on Sunday evening in various parts of the Gaza Strip. PA security sources said the three victims, Ali Makkawi, the commander of the PA Police station in Shati refugee camp, a police officer and a 10-year-old girl, who was run down by a police car, were killed when hundreds of Hamas gunmen attacked the station with rocket-propelled grenades and automatic weapons. They said another 30 people, mostly Hamas members and civilians, were wounded in the confrontations. The attackers also set a number of PA police vehicles on fire. Earlier in the day, Fatah gunmen shot and killed a taxi driver during a protest against the rising cost of gasoline in the Gaza Strip. In the West Bank, unidentified gunmen shot and killed Hani al-Hilakawi, director of the Al-Fawwar refugee camp west of Hebron. No group claimed responsibility and the motive for the murder was unclear. The Hamas clashes began in the Sheikh Radwan neighborhood of Gaza City when PA policemen tried to search a car belonging to Hamas members led by Muhammad Rantissi, son of slain Hamas leader Abdel Aziz Rantissi. The policemen, according to eyewitnesses, opened fire at the car's tires when Rantissi and his cohorts refused to hand over their weapons. In the ensuing gun battle, a police officer and two Hamas members were wounded. Hundreds of residents rushed to the scene and pelted the policemen with stones, forcing them to flee. In a similar incident in the same neighborhood, Fatah gunmen and PA policemen briefly exchanged fire, but no one was hurt. The clash began when policemen tried to raid the home of a Fatah operative in search of weapons. The incident in which a taxi-driver was killed, took place despite a campaign launched by the PA security forces over the weekend to confiscate illegal weapons in the Gaza Strip. Sources in the Gaza Strip said that many armed groups were continuing to roam the streets, defying the PA ban. Eyewitnesses said scores of angry drivers blocked a main highway east of Khan Yunis to protest against the recent rise in gas prices. A number of gunmen belonging to Fatah's armed wing, Aksa Martyrs Brigades, ordered the protesters to reopen the road. When the drivers refused, the gunmen opened fire, killing Yasser Barakeh, 36, and wounding three others. In response, hundreds of protesters pelted the gunmen with stones, forcing them to flee. A spokesman for the Fatah militiamen apologized for the killing and claimed Barakeh had been shot accidentally. He said the protesters had blocked a main highway, preventing a group of Fatah gunmen from carrying out an "urgent mission." He also accused the drivers of attacking the gunmen and trying to steal their weapons. In another incident, unidentified gunmen hurled a homemade bomb at the headquarters of the PA Civil Police on Saturday night. No casualties were reported. PA security sources said policemen stationed at the entrance to the compound opened fire at a suspicious car, but no one was arrested. In Deir el-Balah, hundreds of unemployed laborers demonstrated outside PA offices to demand jobs and money. The demonstrators raised banners calling on the PA to solve the problem of unemployment and poverty in the Gaza Strip. Meanwhile, the PA and Egypt were trying on Sunday to find a solution for the plight of hundreds of Palestinians stranded on the Egyptian side of the Rafah border crossing. Tens of thousands of Palestinians crossed into Egypt illegally shortly after the IDF evacuated the Philadelphi corridor along the border between the Gaza Strip and Egypt. Most of them have returned to the Gaza Strip, but the Egyptian authorities are refusing to allow several hundred to return home. PA Minister of Communications Sabri Saidam said efforts were under way to reach a deal with the Egyptians allowing the Palestinians to cross back into the Gaza Strip.