Mr Sheridan was also arrested in February

The four-hour demonstration was the latest attempt by the Campaign for Nuclear Disarmament (CND) and Trident Ploughshares to bring the Clyde base to a standstill.

However, many workers arrived early and were able to enter the base as normal.

Demonstrators were protesting against the Trident missile system and the military action in Afghanistan.

Strathclyde Police said that about 500 people took part, although the protesters themselves estimated that the figure was closer to 1,000.

The Church of Scotland is against the possession and threatened use of nuclear weapons and we view them as being immoral, illegal and useless

Reverend John Harvey

The force said that all its 168 arrests had been for alleged breach of the peace offences.

Ministry of Defence police also arrested two people at the base - one on suspicion of infiltrating the base illegally and the other for allegedly breaching the peace.

Mr Sheridan was among the first protesters to be taken away by police after they staged a sit-down protest outside the main north gate of the complex near Helensburgh.

As he was led away, the Glasgow region MSP said: "We would much rather the police officers were deployed in more socially useful work this morning.

"Nuclear weapons have no place in the 21st century. We should be channelling resources towards pensioners, the homeless and fighting the war against poverty which are a scar on Scottish society."

Protesters said their actions had been given added resonance following the attacks on the US and the offensive against the Taleban.

Need for peace

They said the attacks reinforced the need for peace and an end to the arms race.

The Reverend John Harvey, of Ardgowan parish church in Greenock, said two Church of Scotland ministers were arrested.

Mr Harvey said John Webster, a retired minister from Glasgow, who now lives on the Isle of Arran, and Flora Munro, a minister from Cults, Aberdeenshire, had been detained by police.

Explaining his motivation for joining the protest, Mr Harvey said: "The Church of Scotland is against the possession and threatened use of nuclear weapons and we view them as being immoral, illegal and useless.

Almost 170 people have been arrested

"Here we have this war against terrorism but can you imagine nuclear weapons being used to deal with that? Of course not.

"It is estimated that �30,000 a day has been spent on nuclear weapons since the birth of Jesus."

The demonstration officially ended when nine protestors staged "a vigil against terrorism and war" outside Argyll and Bute District Court in Helensburgh.

At a protest in February, about 340 people were arrested, including Mr Sheridan, Iain Hamilton QC, George Galloway MP and 15 members of the clergy.

Earlier this month, Mr Sheridan was found not guilty of causing a breach of the peace at that demonstration.

However, the Crown is planning to appeal against the verdict.