Hamas leaders have threatened to execute civilian hostages if Israel continues its retaliatory airstrikes against Gaza. The military wing of the Islamist group said it would kill a captive any time homes were hit “without prior warning”. Israel has been pounding Gaza from the air after Hamas gunmen killed more than 900 people and seized about 130 more in a shock terror attack. Benjamin Netanyahu has called up 300,000 army reservists and signalled a ground assault against the Gaza Strip, which is controlled by Hamas. The Israeli prime minister has reportedly told US President Joe Biden: “We have to go...