Defence and Security Equipment International arms fair (DSEi) begins next week at the ExCeL centre in Docklands - but weapons arrived on Tuesday.
Quakers in Britain told Premier it believes the arms trade has a devastating impact on peace, security and human rights. Many of its members are aiming to stop the event from starting by blocking the entrance to the building.
Ellis Brooks, peace education program manager for the charity said: "The arms industry is one of the factors that we know drives war and armed conflict around the world.
"We know that that's driving civilian casualties and death, so this is not the time to resign ourselves toward the inevitable but to recognise our own responsibility in it."
For one week the Christian organisation will hold worship meetings and candle-lit vigils in solidarity with victims of the arms trade.
So far seven of its members have been arrested.
Brooks told Premier: "We had held a one hour long Quaker meeting for worship outside DSEI today.
"During that meeting for worship some people were sitting in the roads to praise God and share in worship, but for doing that they were arrested."
Brooks defended the group's peaceful protest and said: "It is a personal witness against war and for a more peaceful world, and it is the way many things are changed, through direct action and through civil disobedience."
Quakers in Britain are founding members of Stop the Arms Fair which is a coalition of groups opposing DSEi in East London.
The aim is to build resistance to the arms fair through protest, lobbying, witness, creativity and prayer.
More than 34,000 people are expected to attend the biennial arms fair.
The audience will include over 300 high level speakers from Ministers, Senior Defence Staff and leading industry figures
DSEI claims it has a proven track record of bringing the entire supply chain together on an unrivalled scale.