Palestinian militants in Gaza fired barrages of rockets at Israel for a second day on Wednesday, escalating tensions before a six-month truce is due to expire on Friday. One rocket landed in the parking lot of a busy shopping center in Sderot, an Israeli town near the Gaza border, wounding two civilians. At least 13 more rockets landed in open areas, according to the Israeli police, and the air force destroyed an armed rocket launcher in northern Gaza. The truce, which began on June 19, started to unravel in early November. Hamas, the Islamic group that controls Gaza, wants any extension to be based on better terms, like the opening of the commercial crossings into Gaza. A smaller, more extreme group, Islamic Jihad, said it fired the rockets in retaliation for the killing on Tuesday of one of its operatives in the West Bank during an Israeli Army raid.