A <a href="https://en.wikipedia.org/wiki/Car_bomb" id="mwAQI" rel="mw:WikiLink" title="Car bomb">car bomb</a> explodes outside <a href="https://en.wikipedia.org/wiki/Russell_Street_bombing" id="mwAQM" rel="mw:WikiLink" title="Russell Street bombing">Russell Street Police HQ</a> in <a href="https://en.wikipedia.org/wiki/Melbourne" id="mwAQQ" rel="mw:WikiLink" title="Melbourne">Melbourne</a>, <a href="https://en.wikipedia.org/wiki/Australia" id="mwAQU" rel="mw:WikiLink" title="Australia">Australia</a>, killing one police officer and injuring 21 people.