Oil prices tumbled Thursday, extending steep losses in the previous sessions, as the market braced for a prolonged U.S.-China trade war and digested disappointing manufacturing data. Some analysts also pointed to signs that Middle East tensions are moderating. Brent crude futures sank $3.77, or 5.3%, to $67.22 per barrel around 1:15 p.m. ET (1715 GMT). The international benchmark for oil prices hit a nearly two-month low earlier in the session.