Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: (CNN) Hours after US-led coalition airstrikes reportedly killed dozens of Syrian troops, the US and Russian ambassadors to the United Nations chastised each other outside an emergency Security Council meeting. The strike occurred Saturday in an eastern part of Syria that is not a part of a delicate and nearly week-old ceasefire. The US military said it was targeting ISIS militants and if it hit Syrian troops, it was an accident. Russia and Syria said the strikes prove Washington and its allies are sympathetic to ISIS. The Russian military said 62 Syrian soldiers were killed near Deir Ezzor Airport, according to state media. The UK-based Syrian Observatory for Human Rights put the death toll at 83 and said at least 120 soldiers were wounded.US, Russian in diplomatic row after reported coalition airstrikeUS says it was targeting what it thought were ISIS militants 
 Question:The coalition thought it was going after an _ tank position.

ISIS