Five environmental activists were held on remand over the Easter weekend over protests at oil terminals in Essex and Warwickshire.

Three members of the Just Stop Oil campaign held on remand by Warwickshire police were taken to Coventry magistrates court on Monday morning.

Katheryn Dowds, 28, Jake Handling, 27, and Josh Smith, 29, pleaded guilty to aggravated trespass at the Kingsbury oil terminal after their solicitor did not appear to advise them, according to a campaign source.

Dowds was fined £327, and Handling and Smith were fined £150 each. All were then released, only to be immediately rearrested and held again by police for breaching a high court injunction banning protests at the Kingsbury site, Just Stop Oil said.

“It is thought that they will appear tomorrow at Birmingham county court or Coventry in connection with this charge,” the campaign said.

In Essex, James Skeet, 34, and Stephanie Aylett, 27, were being held after denying charges of aggravated trespass and breach of bail conditions in an appearance at Chelmsford magistrates court on Saturday.

“Magistrates heard how both Skeet and Aylett had been arrested multiple times in Essex since the incidents of disruption began in the early hours of 1 April,” the force said in a statement.

Both had been transferred to prison from police custody on Monday, Just Stop Oil said. Their cases were due to be heard on Wednesday.

Just Stop Oil has been staging direct actions, including mass trespasses, tunnelling and blockades, at oil terminals and in locations around the Midlands and the south-east of England since 1 April in an effort to disrupt the supply of fossil fuels. They have vowed to continue until the government agrees to a moratorium on new fossil fuel projects.

On Saturday, Catherine Maclean, of Hurstpierpoint in West Sussex, became the first person to be convicted over involvement in the Just Stop Oil campaign after admitting aggravated trespass at Chelmsford magistrates court.

Just Stop Oil said there had been nearly 1,000 arrests in connection with the campaign so far. Nine more campaign supporters were released without bail after they appeared at Coventry magistrates court on Saturday. Six pleaded not guilty, one pleaded guilty and two entered no plea, according to the campaign.

Valero Energy, the Texas-headquartered company that owns Kingsbury, has obtained a high court injunction banning protest activity at any of its six UK sites. “The order gives a power of arrest outside the terminal and at the junctions of the roads leading into the zone,” Warwickshire police said.

A spokesperson for Just Stop Oil said: “The courts are complicit in supporting a government that is knowingly fuelling climate breakdown and will have the death of millions on its hands.

“Just Stop Oil supporters have acted in line with their consciences. Just as the suffragettes and the freedom riders did they have chosen not to be bystanders in the face of the catastrophic and ongoing injustice of climate breakdown.

“Some politicians and media pundits have called Just Stop Oil’s demand and its supporters naive. But what is truly naive is the ongoing belief by a political and media establishment that young people will just lie down and die without resisting.”