NEW : Fighting nears densely populated Gaza City , witnesses say . Sources : Reuters and AFP Score: 6 Leader of Gaza City rocket teams is killed , Israel says . Israeli jets apparently violate Egyptian airspace .
NEW : Fighting nears densely populated Gaza City , witnesses say . Sources : Israeli artillery ignites buildings , killing 1 and wounding 49 . Leader of Gaza City rocket teams is killed , Israel says . Israeli jets apparently violate Egyptian airspace .