The price of Brent crude oil dropped on Monday due to weak manufacturing activity in China and a refinery strike by the US unions.

Reuters reported that Brent crude oil futures fell $1.06 to $51.93 a barrel, while US WTI futures dropped $1.01 to $47.24 a barrel.

A private business survey has revealed that China had a reduced factory activity for the second straight month in January.

"Oil production in the shale basins will inevitably decrease as weaker, higher-cost producers shutter their operations."

The prices also dropped due to a sharp decline in US drilling and a strike at nine refineries and chemical facilities across the country.

Nomura was quoted by Reuters as saying: "Oil production in the shale basins will inevitably decrease as weaker, higher-cost producers shutter their operations. This supports our view that oil prices will recover this year and average $60 per barrel for Brent."

Analysts said the prices dropped due to profit-taking following gains in the last week and increasing production by OPEC, which balanced the reduced US drilling.

The news agency reported that international Brent benchmarks rose back above $50 per barrel for the first time since early January.