Reports: Boston Marathon bombing suspect arrested

Investigators have said that a suspect has been arrested in connection with Monday's Boston Marathon bombings, according to US media reports.

The breakthrough reportedly comes from security video of a man dropping off a bag on the street near the finish line before walking away.

The twin blasts killed an eight-year-old boy, a woman aged 29 and a postgraduate student from China.

More than 170 others were wounded.

Officials are due to hold a press conference at 10pm this evening.