A memorial service was held in London on Monday to mark 20 years since four suicide bombers struck a number of city’s subway stations, killing 52 people and injuring more than 770.

Service marks 20 years since London transport suicide bombings killed 52 people

A memorial service was held in London on Monday to mark 20 years since four suicide bombers struck a number of city’s subway stations, killing 52 people and injuring more than 770.