Secretary of State John Kerry claims the Russian government is sending more troops and equipment to Syria in order to protect the Russian soldiers already in the country—a form of self-defense.

“It is the judgment of our military and most experts that the level and type represents basically force protection,” Kerry told reporters.

IHS Jane’s Intelligence Review obtained satellite photos that show “Russian forces developing two additional facilities” on Syria’s coast “at a weapons storage facility and a military base north of Latakia.” Editor Rob Munks believes the Kremlin plans to deploy troops at the locations. From Reuters:

Jane’s, a defense intelligence provider, acquired the images from a commercial satellite division of Airbus Group SE, according to the Wall Street Journal, which first reported on the imagery.

Munks told Reuters one of the sites was located about 4 miles (7 km) north of Latakia and the second was 2 miles (3 km) west of that. The images showed construction of new buildings and grading of terrain, as well as the presence of new tents typically used by Russian military units.

One of the facilities is adjacent to a surface-to-air missile site, Munks added.

CNN reported the Russian government now has “25 fighter and attack aircraft, 15 helicopters, nine tanks, three surface-to-air missile systems and at least 500 personnel on the ground in Syria.”

Kerry admitted the government does not know what Russia hopes to achieve in Syria, but said Moscow and the U.S. want to eliminate radical Islamic groups like the Islamic State (ISIS/ISIL). Russians make up the majority of foreign fighters outside of the Middle East battling ISIS. Jihadists sent a threatening video to Russian President Vladimir Putin last year. Russian propaganda outlet Pravda reported the Russian army “started crushing Islamic State militants that had previously seized the cities of Palmyra and Homs.”

However, both sides disagree on how to tackle the issue. Moscow insists the world needs to join forces with Syrian President Bashar al-Assad in order to defeat ISIS, but the U.S. refuses.

“If they are there to shore up Assad and to simply stand there in a way that provides Assad with continued sense that he doesn’t have to negotiate then I think it’s a problem for Syria and it’s a problem for everybody who wants to bring an end to this conflict which has gone on for too long now,” continued Kerry.

Syrian rebel groups claimed Russia’s intervention “will only lead to an escalation of the war.” They also begged their allies to send them more military aid.

“It is in our calculations that the battle will now extend for more years than it would have without the Russians,” declared rebel fighter Abu Yousef al-Mouajer.

Rebel group Jaish al-Islam took it a step further by declaring war on the Russian troops in Syria. A video from the group shows members “attacking Bassel International Airport, about 20km (12 miles) from Latakia.” The members state Russian troops use the airport as their base. Their rockets are allegedly aimed at a “Russian cargo aircraft, although there is no evidence of this in the video.”