Two English Defence League leaders were arrested as they attempted to visit the Woolwich spot where Drummer Lee Rigby was hacked to death in broad daylight last month.

EDL leader Tommy Robinson and his co-leader Kevin Carroll were detained by police on suspicion of obstructing officers in east London as they attempted to stage what they claimed was a charity walk to Woolwich Barracks via the East London Mosque.

The Metropolitan Police said on Friday that anyone trying to march to Woolwich would be arrested and imposed a route for the walk between Hyde Park Corner and ending at Old Palace Yard, opposite the House of Lords.

In a statement posted on the EDL's Twitter feed, the group said: "Tommy Robinson & Kev Caroll arrested for obstructing the police and carted off."

The statement claimed "negotiations" for their release were taking place and that the pair still hoped to walk to Woolwich to lay flowers. Mr Robinson on Friday replied to a Tweet asking him what weather he was expecting: "ill be in a cell by lunch time so won't matter. Ha ha"

As well as laying flowers in memory of Drummer Rigby in Woolwich, Mr Robinson and Mr Carroll were also walking to raise money for a young girl fighting against neuroblastoma. Throughout the morning, the pair posted pictures on Twitter at London landmarks such as Buckingham Palace, The Mall and the July 7 Memorial in Hyde Park.

Scotland Yard on Friday said it was imposing conditions due to fears that both the march and gathering would "result in serious public disorder and serious disruption to the life of the community" and a breach of the conditions would be a criminal offence.

The police force issued two notices under the Public Order Act based on "current community tensions, the current intelligence picture about Saturday and recent marches and protests held by similar groups". It also said that attempts had been made to liaise with the EDL to facilitate the march and gathering and offered them two alternative routes that avoided Tower Hamlets, home to the East London Mosque.

Alan Green, chairman of the Tower Hamlets Inter Faith Forum, said that an open day was taking place at the mosque. He said: "We are aware that there are those who are fearful of Islam and who seek to undermine the harmony that exists between the faith communities in this borough. Our unity here today makes it very clear that they will not succeed."

A Scotland Yard spokesman said: "At approximately 11.25am today, two men were arrested outside Aldgate East station for obstructing police. They have been taken to a south London police station. Two further men were arrested on suspicion of assault. They have been taken to an east London police station."