The protesters hoisted Russian and St. Andrew’s flags, the latter being the Russian Navy Ensign, according to Interfax.
People have been protesting outside the HQ since 08:00GMT. Several thousand participants have cut the fences, stormed inside and changed the flags on the flagpoles. There have been no immediate reports of violence.
The participants of the rally are currently holding talks with the representatives of the Ukrainian Navy. Russian forces are not party to the negotiations.
There was an immediate alert on the territory of the HQ and the Ukrainian servicemen lined up in front of the protesters, reports Interfax. The line was broken by cars belonging to activists that entered the territory.
The protesters are calling upon the Ukrainian servicemen to leave the HQ. An ambulance has been called as a precaution.
Some of the participants of the rally have been singing the Russian anthem.
UkrStream.TV cameras which are currently recording the situation near the headquarters of the Ukrainian Navy show no violence on the precinct.
According to Sevastopol news websites, the Commander of the Russia’s Black Sea Fleet, Vice-Admiral Aleksandr Vitko, has just arrived in the HQ of the Ukrainian Navy and negotiations are underway.
Vitko arrived at the HQ 30 minutes ago and is currently holding talks with Rear Admiral Sergey Gaiduk of the Ukrainian Navy.
After the negotiations, Vitko left the Ukrainian Navy HQ and refused to comment on the results of the talks with Gaiduk.
According to Reuters, nearly a dozen unarmed Ukrainian servicemen have walked out of HQ.
Earlier, there were reports of possible provocations. Some unidentified men tried to enter the building. However, the attempts failed due to Self-Defense Unit guards and Crimean Cossacks.
Ukrainian armed forces commander Mikhail Kucin, has informed his Russian counterpart Valery Gerasimov that he has authorized the use of military force by troops stationed in Crimea, according to Ukraine’s Defense Ministry.
In a phone conversation with Gerasimov, Kucin has emphasized de-escalation and a political solution to the crisis, rather than a violent one. The green light to use force has been given by him in the aftermath of the events in Simferopol, which have led to the death of one Ukrainian soldier and another from the Crimean Self-Defense Forces, while two others were injured.
On March 16 Crimea held a referendum where over 97 percent of its citizens voted for joining Russia. Two days later, the Autonomous republic of Crimea and Sevastopol, a city with a special status, became federal objects of the Russian Federation.