CAIRO/WASHINGTON/DUBAI — Iran said on Wednesday it had attacked 10 ships near the Strait of Hormuz after the U.S. sank five Iranian oil tankers, in the biggest declared wave of tit-for-tat attacks on shipping by both sides since the start of the six-month-old war. The attacks sent the price of oil surging, with benchmark Brent crude futures breaching $100 a barrel for the first time since July. At least one seafarer aboard a tanker was reported killed and another listed as missing. Iran also said it had fired ballistic missiles at a base used by U.S. forces in Jordan. Attacks by both sides since the end of August have shattered a month of relative calm, with the U.S. and Iran hitting military, shipping and energy assets. The Revolutionary Guards said they would sharply escalate their response to any further attacks, hitting 20 targets if the enemy struck two or three. Iran would soon release maps of a new, enlarged off-limits zone at sea that would extend as far as Chabahar on the far reaches of Iran's coast near Pakistan, the Guards said. Recent days have also seen an escalation in fi