4586
In what may have been a ripple effect of the Middle East crisis , an explosion today killed at least four sailors on a US Navy destroyer in the Yemeni port of Aden .
 location: Middle East; date: today; cardinal: at least four; organization: US Navy; national religious political: Yemeni; geographical social political: Aden
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: date, organization, person, geographical social political, national religious political, facility, cardinal, location, work of art, law, event, product, ordinal, percent, time, quantity, money, language 
Text: {0} 
Answer:
 location: Middle East; date: today; cardinal: at least four; organization: US Navy; national religious political: Yemeni; geographical social political: Aden