In Seoul, North Korea recently tested a small rocket engine, a monitoring group said today, after a US official had reportedly suggested the test could be a step to develop an intercontinental ballistic missile.<br/><br/>However, it was not clear whether the test, conducted at the North's Sohae satellite launch site, involved an ICBM engine.<br/><br/>Based on satellite imagery analysis, the Washington-based group said the nuclear-armed state appeared to have conducted the test" around 22nd June.<br/><br/>The impoverished, isolated North has staged two atomic tests and dozens of missile launches since the beginning of last year. It raised concerns over the gradual upgrade in its disputed weapons programmes and multiple rounds of United Nations sanctions.