GUN battles between Israel and militants from Hamas, Islamic Jihad and smaller Palestinian factions intensified overnight into some of the fiercest in months in both northern and southern Gaza, both sides said. Israeli tanks reached densely populated neighbourhoods and narrow alleyways of the militant stronghold of Jabalia in the northeast, facing heavy resistance. Residents said the army destroyed clusters of homes there in areas where they had not invaded before. The armed wing of Hamas ally Islamic Jihad said its militants killed and wounded Israeli foot soldiers during fierce clashes in eastern Jabalia, the biggest of eight refugee camps built…