BEIRUT (Reuters) - The Syrian army said on Saturday that Turkey had recently increased supplies of weapons, ammunition and equipment to what it described as terrorists in Syria, and accused its northern neighbor of firing shells at Syrian army positions.

“We have certain information that the Turkish government has recently increased its support to the terrorists and the level of their supplies of weapons, ammunition and equipment necessary to continue their criminal acts,” an army statement said.

The Syrian government describes as terrorists all the groups fighting President Bashar al-Assad in the 4-1/2-year-long war that has moved into a higher gear since Russia intervened militarily on the side of Damascus with air strikes on Sept. 30.

Tensions at the Syrian-Turkish border have risen since Turkey shot down a Russian warplane on Tuesday. Many of Russia’s air strikes have hit rebels backed by Assad’s foreign enemies including Turkey, Saudi Arabia and the United States.

The statement by the Syrian army command alleged that weapons were being delivered in shipments which Turkey claimed to be humanitarian assistance. It also alleged the weapons were supplied in exchange for looted Syrian and Iraqi antiquities and oil sold at low prices.

Turkish President Tayyip Erdogan has denied accusations his country purchased oil from Islamic State, saying anyone making such claims must prove them.

The Syrian statement also said Turkey had fired a number of mortar bombs toward Syrian army positions on Friday night from a location just over the border from Latakia province in northwestern Syria.

A Syrian military source told Reuters this week rebels were making heavy use of U.S.-made anti-tank missiles paid for by Saudi Arabia and supplied via Turkey in recent weeks and the weapons are having an impact on the battlefield.

The so-called TOW missile is the most potent weapon in the rebel arsenal, and have appeared more frequently in battle in recent weeks. Rebels were shown using one to destroy a grounded Russian helicopter this week.

The army statement said: “The Turkish authorities deliberately created a state of security chaos at the Syrian-Turkish borders, leading to the easy movement of terrorists from Syria to Europe to carry out their terrorist crimes.”

Russian President Vladimir Putin said on Tuesday that large quantities of oil and oil products from territory captured by Islamic State had been arriving in Turkey.