The dollar hit a fresh 40-year high against the yen and strengthened against the euro as oil prices climbed and the European Central Bank kept interest rates unchanged. The dollar index rose 0.32% to 101.47, while the euro fell 0.35% to $1.137. The yen weakened 0.49% to 163.93 per dollar, touching its softest level since November 1986. Brent crude reached $100.42 a barrel, up 6.75%, after Yemen's Houthis said they struck two Saudi oil tankers. Markets priced in an 83.2% chance of a Federal Reserve rate hike in September, up from 52.4% a week ago.