Mumbai, June 23 -- The Indian rupee edged lower in opening trades on Monday tracking firm dollar overseas. Escalating tensions in the Middle East drove investors to the safe haven currency and send oil prices soaring. INR opened lower by around 18 paise at Rs 86.75 per dollar. On Friday, rupee snapped its three-day losing streak and settled with a gain of 18 paise at 86.55 against the US dollar. Indian shares also look set to open on a sluggish note Monday, tracking weak cues from Asian markets and a spike in oil prices that is also adding pressure on the local unit. Asian stock markets are trading mostly lower on Monday, following the mixed cues from Wall Street on Friday, amid escalation in the middle-east conflict after the U.S. joined...