Yet another bomb has been found and made safe in a flat in St Petersburg by Russian police, three days after a suspected bomber on the city's metro killed 13 people.

A city official said several suspects were held when police raided the flat early on Thursday
Neighbours were moved away and witnesses said three men were led out in handcuffs, said reporters
The main suspect in the metro bombing, Akbarzhon Jalilov, died in the attack.
Aged 22 and from the Central Asian republic of Kyrgyzstan, his remains were identified by his parents on Wednesday.
The flat raided at around 05:00 local time (01:00 GMT) on Thursday was in Tovarichesky Prospekt in the east of St Petersburg. "An explosive device found in the flat has been made safe. Several suspects have been arrested; they didn't resist and there's now no threat to local people," the head of the local authority Konstantin Serov was quoted as saying.
Sources told reporters, that investigators were examining possible links between the three men and the alleged bomber. Witnesses said the three suspects were all from Central Asia. Jalilov himself had been renting a flat in the north of Russia's second city.
While searching the flat they had been living in, investigators said they had found "items of significance for the investigation".