London, April 20 -- Observed transits of commercial ships through the Strait of Hormuz have come to a halt following a brief surge on Saturday as tensions ratcheted higher after vessels came under gunfire in the waterway and Iran warned against crossings. No crossings were seen on Sunday, according to tracking data compiled by Bloomberg as of early afternoon in London. At least 13 oil tankers turned back toward the Persian Gulf on Saturday, abandoning attempts to leave that began after Iran's Foreign Minister Abbas Araghchi announced a day earlier that the strait was open. But Tehran again shut the waterway following a refusal by the US to lift its own naval blockade of Iran's vessels. It followed a period of chaos when some ships tried to ...