Two pregnant women and 15 children were among 68 people found locked into a container at a port in the UK.

Four Polish lorry drivers were arrested after the discovery at Harwich International Port in Essex at about 10pm yesterday.

On board the lorries were 35 Afghan nationals, 22 Chinese nationals, 10 people from Vietnam and one Russian.

Seven of them, including the two pregnant women, were taken to Colchester General Hospital to be checked, before being released into the care of Border Force officials.

A Home Office spokesman said: "We can confirm Border Force officers discovered 53 adults and 15 children during a proactive search of four lorries which had arrived at Harwich port from Holland on Thursday evening.

"Four Polish nationals, who were driving the vehicles, have been arrested on suspicion of facilitating illegal immigration.

"They have been taken to separate police stations and will now be questioned by the Home Office's criminal investigations team while inquiries continue."

All 68 individuals are now in the custody of the Border Force.

A spokesman for the Essex port said the people were discovered on vehicles that had arrived on a ferry from Holland.

A spokeswoman for Stena Line said: "We can confirm that four different lorries carrying 68 clandestines were stopped by Border Force at Harwich International Port last night as they disembarked from the Stena Hollandica."

She added that the ship left the Hook of Holland at 2.15pm and arrived in Harwich at 7.45pm yesterday.

The British Red Cross said staff and volunteers were responding to the immediate needs of the 68 immigrants found on the lorries.

It confirmed that all of the non-European migrants were found locked in four separate vehicles, and that the charity was providing practical and emotional support, including blankets, food and hygiene packs to those affected.

A spokesman for the UN High Commissioner for Refugees (UNHCR) said the priority was to find out who the people are, their needs, and whether they are entitled to any protection.

He continued: "The situation we have here is consistent to what we have seen elsewhere. It shows the desperation and vulnerability of those who might have been seeking protection across the UK."