Two machete-wielding teens who smiled as they fatally stabbed a 14-year-old schoolboy on a bus have been jailed for life.

Aspiring rapper Kelyan Bokassa was stabbed 27 times as he travelled on a route 472 bus in Woolwich, southeast London, on the afternoon of January 7.

The young boy called 'I want my mum' after he was mortally wounded by the two youths, aged 16, in front of horrified passengers.

The duo fled the scene and hid for six days before they were eventually discovered and arrested after being identified by CCTV footage.

Before the brazen attack, CCTV showed Kelyan boarding the bus shortly after 2pm, heading to his appointment at Woolwich Youth Justice Centre.