Protest group Just Stop Oil says it has targeted key oil terminals across the country.
Six people have been arrested after a campaign group targeted fuel terminals.
The arrests were made at three locations in Thurrock, Essex Police said.
Oil company Exxon Mobil has temporarily suspended operations at three other terminals due to a series of co-ordinated “small protests”.
Campaign group Just Stop Oil said it was targeting “key” sites in Birmingham, West London and Hythe in Kent.
Operations from these locations had been halted, Exxon Mobil said.
The Essex force tweeted: “We are currently dealing with three incidents in #Thurrock, where a group of people are reportedly blocking the roads.
“Six people have been arrested so far. It is impacting Navigator Fuel Centre, Esso in #Purfleet, and Askew Farm Lane.
“Drivers are asked to avoid the area.”
The group claimed that more than 30 young people climbed on top of tankers at Navigator Oil Terminal, Thurrock.
Exxon Mobil said its terminals at Purfleet and Avonmouth were not affected by the demonstrations
It apologised for any inconvenience.
West Midlands Police and fire services said they were in attendance at Tyburn Road, and advised those travelling to avoid the area.
Just Stop Oil said in a statement: “The Just Stop Oil coalition is demanding an end to the government’s genocidal policy of expanding UK oil and gas production and is calling on all those outraged at the prospect of climate collapse and suffering from the cost-of-living crisis to stand with us.
“Ordinary people can no longer afford oil and gas, it’s time to just stop oil.”