The United States and Europe are seeking to open a sea route that would bring humanitarian aid into Gaza, as alarm grows over the spread of hunger among the besieged territory's 2.3 million people. However, aid officials say deliveries by ships or recent airdrops are far more costly and inefficient than sending trucks by land. And on Friday, five people in Gaza were killed and several others injured when airdrops malfunctioned and hit people and landed on homes, Palestinian officials said.