The Sikhs in the City (SITC) running group from Ilford will don black armbands in Sunday’s London Marathon to remember those killed and injured by blasts at the Boston Marathon.

Three people were killed and more than 100 were injured following two large explosions at the final stretch of the Boston race, the world’s annual oldest marathon, yesterday.

The cause and motivation remains unknown, with two other unexploded bombs reportedly found near the end of the course.

SITC club secretary Harmander Singh, 53, said he was saddened by the scenes of panic among runners and spectators on television last night.

Harmander, one of the group’s founder members who coached 102-year-old Ilford runner Fauja Singh through his remarkable marathon-running career, said he remained determined to take part in Sunday’s marathon, his 29th.

He said: “It’s made a stronger resolve.

“We want to stand up against these idiots, to show the resolve that society as a whole needs to stand up and needs to be counted.”

Six group members from Redbridge, including Harmander, will take part on Sunday, along with around four SITC members from Scotland.

He is also trying to find a Boston flag to wear over the London course’s 26 miles as a tribute.

They will gather at Harmander’s Wellesley Road home beforehand to say a prayer and remember those affected by the Boston explosions.

Ciaran Canavan, a committee member of the East London Runners group which meets at Wanstead Leisure Centre in Redbridge Lane West, said he was “not aware” of any group members running in Boston yesterday.

The group has more than 150 members and around 25 runners will take part in London.

He put out messages on social networking sites following the explosions to speak to members and see if there was any way they can pay their respects on Sunday.

He said: “As far as I know, no-one travelled this year.

“We’re a resilient group and we’re not going to let this situation deter us.

“The [London Marathon] is going ahead and they’re checking the security.

“We will hold our heads up high.”

A Foreign Office spokesman said: “We are in close contact with the local authorities [in Boston].

“We are not aware of any British nationals being injured but we’re closely monitoring the situation.”