Israeli forces have raided two Gaza refugee camps, killing at least 12 Palestinians and wounding 20 more. Witnesses to the Sunday raid said soldiers shot dead a 15-year-old and other young men who attempted to halt the Israeli military as it forced its way into the camp. Dozens of armoured military vehicles took part in the sweeps for Hamas members in al-Buraij and Nusairat camps in the central Gaza Strip. Tanks choked the main roads to the camps and explosions thundered in the early morning. Israeli commentators have speculated the army would step up operations against Palestinians in the Gaza Strip before Prime Minister Ariel Sharon puts into motion an evolving plan to evacuate some illegal settlements in the area. **Raiding refugees*** But according to an Israeli military source, the raid was a "pinpoint operation against the terrorist infrastructure in the central Gaza Strip." The source said Palestinians from the refugee camps in the area had been attacking Israeli convoys and firing mortar bombs and Qassam rockets at Jewish settlements. The raid comes after Palestinian resistance fighters mounted an elaborate but unsuccessful attack on Saturday at the Israel-Gaza border in which fighters used fake Israeli jeeps. **Failed operation*** However, Israeli border guards opened fire on the first jeep, killing two men in the lead vehicle before fighters could launch their attack. The second jeep exploded prematurely - killing its occupants and two policemen uninvolved in the attack. For thousands of Palestinian labourers, Erez is a gateway to coveted jobs in Israel and in an Israeli-run industrial zone at the crossing. There were no Israeli casualties in the Erez operation. **PHOTO CAPTION*** Palestinian boys look at mourners during the funeral of policeman Basheer Abu al-Amreen 28, who was killed in a blast at Erez crossing in the Gaza Strip March 6, 2004. (Photo by Mohammed Salem/Reuters)