Homes of Ukrainian Svoboda party members are being searched in the inquiry into riots, which happened near the Verkhovna Rada building on August 31, 2015, and killed four National Guard servicemen, advisor to the Ukrainian interior minister Ivan Varchenko has said.

"The Investigative Department is holding the search in connection with the August 31 case. Let me remind you that yesterday a fourth National Guard serviceman died from injuries suffered on August 31. He was in coma and never woke up. So, four people are now dead and more than 138 are injured," Varchenko said in a program aired by Channel 112 on Saturday.

He said that homes of all suspects were being searched.

Varchenko added that 20 suspects had been detained in the inquiry into the August 31 case, and another 200 persons had been identified as witnesses.

Searches of the homes of Svoboda Audit Commission head Oleh Helevey and members of the Svoboda Odesa regional organization Hleb Hromov and Oleksandr Stankov began on Saturday.

The police are also searching homes of the wife of Svoboda Kyiv regional organization head Ihor Sabiy, No 1 on the Svoboda list in the Odesa Region Council Kost i antyn Vasylkevych and Ukrainsk y Tyzh den journalist, volunteer Valeria Burlakova.