Search for cascade events with Baikal-GVD demonstration cluster 'Dubna'

Deep underwater neutrino telescope „Dubna“ – the first, demonstration cluster of Baikal-GVD, has been deployed in April 2015 and was operating up to February 2016 in Lake Baikal. In 2016 this array was upgraded to baseline configuration of GVD-cluster by adding additional 96 optical modules. The next step of array extension was provided in 2017 by deployment of second GVD-cluster in Lake Baikal. We present here preliminary results of a search for cascade events using data sample recorded in 2015 by Dubna array and corresponding to 41 live days of data taking.