The first weapons systems have arrived the Russian base in Syria, Western military and intelligence sources said on Saturday, adding that these new weapons are "defensive by nature." These weapons, they claim, are to be used for base security as opposed to offensive military capabilities, as part of what the West believes is stepped-up military support for embattled President Bashar Assad.The equipment consists of a half dozen howitzer artillery pieces and a control system for surface to air missiles, sources said. There are now about 200 Russian naval infantrymen at the base who would make up the base protection force. Enough housing has been erected to house 1500 personnel, and more is expected to be built as the the force grows.However, Western sources are still unclear as to the purpose of establishing the Russian base in Syria, as Russia remains elusive on their plans for using the base in the future. Still, there is a consensus among the sources, including those from the Israeli military, that Russia together with Iran have enhanced their presence in Syria in a desperate attempt to prevent the total collapse of the Assad regime. The regime has suffered serious losses as the struggle for power continues in the unstable region. The Syrian army now controls only 25% of what used to be Syria before the civil war began four and half years ago. The area still under the regime's control includes Damascus and the coastal strip where the majority of the Alawites sect is concentrated and the roads connecting them.Sources also estimate that Russia is trying to increase its control in the region, and plan to enlarge its presence at the strategic Tartus port, located off the coast of Syria, which is controlled by the Russia navy in the Mediterranean.Reuters contributed to this report.