Troops of the Southern Transitional Council (STC) on Saturday tightened their grip on the strategic Yemeni island of Socotra after expelling loyalists of the Muslim Brotherhood group.

A security official based in Socotra confirmed that "the southern troops were largely deployed across Socotra and have completely gained total control over the strategic island."

"Officials of Socotra's local authority declared their outright support for the southern forces that began securing all the state facilities there," the source said on condition of anonymity.

He affirmed that all offices of the local authority have resumed work and begun offering services for the local residents in Socotra.

Earlier in the day, hundreds of Socotra's local residents staged a large demonstration in front of the local authority headquarters to show support for STC's troops.

Witnesses told Xinhua that "people went out to the streets in Hadibu, the capital of Socotra, waving flags of former South Yemen and happily welcoming the arrival of the southern troops."

A leading member of the Aden-based STC, a powerful ally of the Saudi Arabia-led coalition, confirmed that STC has started implementing self-rule in Socotra and held a number of meetings to discuss the situation there.

"During the past period, some elements used Socotra as a hotbed for illegally smuggling weapons to abort the efforts of the Saudi Arabia-led coalition fighting Houthis in Yemen," the STC official said anonymously.

"From now on the southern troops will secure Socotra and closely cooperate with the Saudi-led Arab coalition to curb the activities serving other foreign agendas in the country," he added.

Local observers believe that a number of reasons enabled the STC in seizing the strategic island.

"Unlike the Muslim Brotherhood-affiliated Islah party, the STC and its troops are widely welcomed by the people and also the local figures or tribesmen there," said Ali Bin Hadi, a military observer based in Aden.

"The STC's southern troops are strongly aligned with the Saudi-led Arab coalition in fighting some countries' influence in Yemen while the Muslim Brotherhood did the opposite things," he added.

On Friday, armed confrontations erupted between the STC's troops and forces loyal to the Islah party, part of Yemen's government, over the control of Socotra.

Yemen's government condemned the STC's escalation in Socotra and urged forces of the Saudi Arabia-led coalition stationed there to intervene or conduct a mediation to cease the conflict, but received no reply.

The Yemeni government based in Saudi Arabia demanded an immediate cessation of the STC's actions and insisted on unconditional withdrawal of the southern troops from the island.

Socotra is located in one of the busiest shipping routes in the world and Yemen's warring factions sporadically engage in armed confrontations over establishing military bases there for controlling the strategic island.

The Socotra archipelago is also a UNESCO World Heritage site, with rich and unique biodiversity.