Oil prices edged up on Tuesday, supported by a softer dollar and a United States plan to restock petroleum reserves, but gains were capped by uncertainty over the impact of rising Covid-19 cases in top oil importer China. Brent crude futures were up 24 cents, or 0.3 per cent, at $80.04 a barrel at 0402 GMT, adding to a 76-cent gain in the previous session. US West Texas Intermediate (WTI) cr