The funeral is due to be held of Russian opposition politician Boris Nemtsov, who was shot dead in Moscow.

The service at Moscow's Troyekurovskoye Cemetery will follow a public ceremony at the Andrei Sakharov rights centre.

Mr Nemtsov, a fierce critic of President Vladimir Putin, was killed on a bridge near the Kremlin wall on Friday night.

Several prominent foreign and Russian figures have been prevented from attending the funeral.

•    Bogdan Borusewicz, the Polish senate speaker who was to have led a delegation from his country, was denied a visa. The Russian embassy in Warsaw said Mr Borusewicz was on the list of Polish officials barred from travelling to Russia, a list drawn up after the EU imposed sanctions on Russia over its involvement in Ukraine

•    Latvian MEP Sandra Kalniete told the BBC she had been refused entry into Russia at Sheremetyevo airport in Moscow without a proper explanation

•    Russian opposition leader Alexei Navalny, who is in custody for 15 days for handing out leaflets publicising a demonstration, has not been allowed out of custody to attend

Shot four times

Tens of thousands of people marched through central Moscow on Sunday to honour Mr Nemtsov, with the opposition claiming some 50,000 people had attended the event.

Mr Nemtsov had been due to lead an opposition march that day, but his killing turned the event into a mourning rally.

Nemtsov allies have accused the Kremlin of involvement but President Vladimir Putin condemned the murder as "vile" and "provocative", vowing to find the killers.

Russia's Investigative Committee said it was looking into a number of possible motives for the murder.

They include his opposition to the Ukrainian conflict, Islamic extremism - Mr Nemtsov had Jewish ancestry although he had become Orthodox Christian - and an opposition "sacrifice" of its leader to destabilise the state and undermine the president.

Mr Nemtsov, 55, had been walking home from a restaurant with his Ukrainian girlfriend, Anna Durytska, when he was shot four times.

Ms Durytska, a 23-year-old model, told Russia's independent Dozhd television she had not seen the attacker.

"I don't know where he came from but he was behind," she said.

"I turned round and all I saw was a light-coloured car. I saw neither the brand nor the licence plate of the car that was driving away."

The Federal Protective Service, in charge of presidential security, said its surveillance cameras had not recorded the shooting because they were pointed towards the Kremlin.

Ms Durytska has been allowed to return to Ukraine from Russia after being questioned by police.

Source: BBC