The Indian equity benchmarks erased early gains to end lower for second straight session as investor sentiment was shaken after fresh geopolitical tensions emerged between Ukraine and Russia. Russian news agency Sputnik reported that Ukraine violated ceasefire after Ukrainian Armed Forces fired mortar shells and grenades on self-proclaimed Luhansk People's Republic at 2:30 am GMT. Meanwhile, heightened volatility during the session owing to weekly expiry of index futures and option contracts also added to the risk sentiment, analysts said.