An Israeli tank wounded eleven Palestinians, two critically, when it opened fire on a group of militants east of Gaza City on Wednesday, an emergency services spokesman said. "Eleven Palestinians were injured by tank shell in an area east of Gaza City. Two of them are in critical condition," Adham Abu Selmiya of the Hamas-run rescue service told AFP, saying they had been taken to the city's Shifa hospital. Three of the injured were militants from the Al Quds Brigade, the armed wing of the radical Islamist Jihad movement, a statement from the group said. "Three of our fighters were injured while firing two mortar shells towards Israeli tanks which were operating inside the (Gaza) border," the statement said. The Israeli army said troops opened fire after coming under attack. "This morning an Israel army force was engaged in a regular patrol along the Gaza border when an explosive device was detonated near the force and a mortar shell fired at it," a military spokeswoman said. "The force spotted several terrorists and opened fire on them, identifying a hit," she said, adding that militants had placed 12 bombs along the border fence in the last two months. Following the incident, the Al Quds Brigade said it fired three mortars into Israel, targeting Kibbutz Nahal Oz, east of Gaza City. The military confirmed mortars had fallen in the region, without causing casualties. Israel public radio said one of the mortars hit a football field. In a separate incident, another two Palestinians were moderately wounded by Israeli gunfire as they were collecting gravel north of the town of Beit Lahiya near the border, he said.