President Barack Obama promised a grieving Boston to hunt down whoever was responsible for the deadly bombing at the marathon, while investigators focused on a man seen dropping off a bag and walking away from the site of the second of Monday’s two explosions.

Cardinal Bernard Law, the figure at the centre of renewed anger over abuse by Catholic priests in the Boston area, was making an unexpected visit to the Vatican today.

Facing rekindled outrage from priests and parishioners over new revelations of clergy misconduct, Boston Cardinal Bernard Law stayed away from the Cathedral of the Holy Cross today as protesters renewed calls for his resignation.