Oil prices fell on Monday after US energy firms added rigs for the first time this year in a sign that crude production there will rise further.
US spot crude oil futures were at $53.37 per barrel at 0027 GMT, down 32 cents, or 0.6 per cent, from their last settlement.
International Brent crude oil futures were at $61.37 a barrel, down 27 cents, or 0.4 per cent.
Analysts said high US crude oil production, which hit a record 11.9 million barrels per day (bpd) late last year, was weighing on oil markets.
In a sign that output could rise further, US energy firms