Definition: In this task, you need to generate an appropriate title for the given summary of some paragraph. The generated title must be short and should include the main topic of the given text. Your summary should be less than 20 words long.
Input: US investigators believe Iran or groups it supports used explosives to damage four ships off the United Arab Emirates on Sunday, media reports say.

US 'blames Iran' for damage to tankers in Gulf of Oman