Palestinian women hold pictures of loved ones during a protest calling for their release form Israeli jails in Gaza City, April 30 2007. Khaled Meshaal, the political chief of the Palestinian Islamist movement Hamas warned of a "big explosion" in the Middle East if Palestinian problems are not solved. Meshaal again deplored the embargo on direct aid to the Palestinian government that was imposed by the European Union and the United States last year after Hamas formed a cabinet alone following its clear victory in parliamentary polls.