Health officials say at least seven were killed and 39 more injured in clashes in Ukraine . Ukraine 's deputy interior minister says about 20 militants killed , 4 detained in Mariupol . ` ` We will overcome all the difficulties , '' says Russian President Vladimir Putin . Putin watches as warships and military aircraft take part in displays in Sevastopol , Crimea .
Health officials say at least seven people killed and 39 more injured in clashes in Mariupol . Ukraine 's acting interior minister says about 20 militants killed , 4 detained in Mariupol . `` We will overcome all the difficulties , '' says Russian President Vladimir Putin . Putin watches as warships and military aircraft take part in displays in Sevastopol , Crimea .