U.S. oil prices fell to around $56 a barrel after the OPEC Plus cartel said it would bring more oil to market.

Crude oil futures tumbled at the open Sunday after OPEC decided to boost output. WTI crde (CL1:COM) -3.8% and Brent (CO1:COM) -3.5% dropped more than 3%. Eight members of OPEC+ on Saturday announced a second straight monthly increase of 411K barrels of crude per day for June.

Oil prices dropped Monday, as the Organization of the Petroleum Exporting Countries and its allies agreed to boost output again in June, raising concerns about a potential oversupply at a time when markets are grappling with the uncertainties of a global trade war.