A teenager has been stabbed to death in south-east London .
Police were called at about 21:40 GMT to Topham House in Prior Street, Greenwich, following reports a man was unresponsive after being stabbed.
The 18-year-old died at the scene. A 17-year-old boy has been arrested in connection with the death and taken to a police station for questioning.
More than 120 murder investigations have been launched across London this year.