Israel announced Saturday that it had killed three more senior leaders in the Iranian military, further diminishing hopes that there might be a swift end to the escalating conflict, even as officials from multiple Muslim-majority countries are expected to call for a ceasefire in Istanbul this weekend.

The S&P 500 and Nasdaq ended lower on Friday, with investors on edge over the Iran-Israel conflict heading into the weekend, as the U.S. considers whether to get involved. Trading was choppy for much of the session.