Amid ever-rising tensions in Lebanon, the UN Security Council called Wednesday on the country’s political factions to resist falling into a civil war and indicated concern over the involvement of Lebanese terror group Hezbollah in fighting across the border in Syria.

United Nations Secretary General Ban Ki moon said he was worried by Hezbollah involvement in the Syrian civil war, and the response by anti-Hezbollah groups.

“The implications of these developments for Lebanon’s stability, and indeed for the region, are serious,” he said, according to a UN press statement.

Hezbollah, an ally of Syrian President Bashar Assad, has backed Damascus against opposition forces seeking to fell the regime, sending thousands of fighters into the country. Fighting between the Shiite group and Sunni opponents has also spilled into Lebanon.

Instances of sectarian violence in Lebanon have grown common over the past few months. Sunnis in the country, many of whom support Syria’s rebels, have grown increasingly agitated by Hezbollah’s contribution to the region’s instability.

On Tuesday, a car bomb detonated at a Hezbollah stronghold, wounding at least 53 people in what officials called the “most serious” crossover violence yet.

The Security Council condemned the violence perpetrated by armed groups in Lebanon, and stressed “the need to support the security and judicial authorities in combating impunity.”

“The Security Council calls upon all Lebanese parties to recommit to Lebanon’s policy of disassociation, to stand united behind President Michel Suleiman in this regard and to step back from any involvement in the Syrian crisis,” read an official statement issued by the council.

Although the statement did not specifically mention the Lebanese terror group, due to Russian objections, a UN official told Reuters that the Security Council did in fact intend to single out Hezbollah.

The Council also voiced concern over the abundant flow of refugees into Lebanon, underlining the fact that the civil war in Syria may have serious implications for Lebanon’s future.

Addressing the international community, the council called to “assist the Lebanese authorities who face extraordinary financial and structural challenges as a result of the refugee influx.”

Since the start of the Syrian conflict in 2011, over 1.7 million people have fled Syria to neighboring countries.

Earlier Wednesday, Lebanon’s UN ambassador said his country was being overwhelmed by more than a million Syrian refugees who have crossed the border to flee the war.

Although the UN’s figures point to 587,000 Syrian refugees who have entered Lebanon since the conflict began almost three years ago, Ambassador Nawaf Salam told reporters that many more have come into the country without registering. He put the current total at “a million-plus.”

Still, Salam vowed that “Lebanon will not close it borders. It will not turn back any refugees.”

Lebanon is a country of just 4 million people, so the huge numbers of refugees are politically sensitive in a nation that endured its own civil war in the 1980s.

The Associated Press contributed to this report