Boris Nemtsov murder: Former PM Kasyanov pays tribute

Thousands of people are expected to attend a memorial rally in memory of Boris Nemtsov in Moscow on Sunday.

Mr Nemtsov - a leading opposition politician - was shot dead on Friday. He had been planning to hold a march opposing the government - which has now been turned into a memorial to him.

Sarah Rainsford has been speaking to the prominent opposition leader and former Prime Minister Mikhail Kasyanov about Mr Nemtsov.