Seven Palestinians, including a mother and her son, were injured on Saturday after two shells fired by an IDF artillery cannon landed in the village of Beit Hanoun in the Gaza Strip. The IDF said it was checking the validity of the reports but confirmed that cannons had fired close to 300 artillery shells since Friday at Kassam launch sites in the northern Gaza Strip. Palestinians said that one of the shells landed on a house in Beit Hanoun while the second shell landed ten minutes later on a nearby street. Two of the wounded were reported to have been in serious condition. The army said that it regretted the incident but declared that it would continue firing artillery shells at Kassam launch sites as long as Palestinian terror groups continued firing the rockets at Israeli targets. On Friday, Palestinians fired four Kassam rockets at Israel. No one was injured in the attacks. On Thursday, Defense Minister Shaul Mofaz ordered the IDF to step up its operations in northern Samaria against Islamic Jihad - behind the latest suicide attacks in Israel - as well as the ongoing anti-Kassam operation in Gaza. Security officials told Mofaz that Fatah - the longtime dominant Palestinian party - had stepped up its terror activity and was currently behind some 50 percent of Palestinian terrorism. Mofaz also ordered a continued closure on the West Bank until after Independence Day on Wednesday. "The only way to stop Palestinian terror is to continue investing in arrest operations in the West Bank," a security official said. On Friday, a senior military officer said that Israel wanted to avoid a ground operation in Gaza but would launch one if the Palestinians continued to increase their capabilities in a "significant way." He cited the entrance of Katyusha rockets as a possible reason for extensive military action. Last month, Islamic Jihad fired a Katyusha rocket into southern Israel for the first time. The rocket caused no damage, but had longer range and was more powerful than the primitive Kassam rockets usually fired by the Palestinians. In West Bank violence, police were investigating reports that settlers had attacked a group of Palestinians from Kfar Rair near Ramallah and had shot and killed a Palestinian-owned horse. Earlier in the day, settlers clashed with security forces near the Maon Farm outside of Hebron after the settlers prevented Palestinian students from passing nearby the settlement on their way home from school.