The rebels are taking a beating, which means Obama is that much closer to jumping in.

BEIRUT (AP) — Syria’s main opposition alliance on Wednesday urged fighters from around the country to reinforce a rebel-held town under attack by President Bashar Assad’s troops and their allies from the Lebanese militant Hezbollah group.

With its appeal, the Syrian National Coalition sought to bolster embattled rebel forces in Qusair who for a fourth straight day Wednesday came under fierce assault by government troops. The town, which is near the border with Lebanon, lies at the heart of a government offensive to secure a strategic strip of land running from the capital, Damascus, to the Mediterranean coast and Syria’s seaports.

The Iranian-backed Hezbollah group has been fighting alongside Syrian regime forces in the town and surrounding areas in Homs province for weeks.

“Forces from outside Syria” aim to destroy Qusair and rebels should join the fight to “rescue” the town, George Sabra, the acting chief of the Syrian National Coalition, said in a statement. He also urged Lebanese authorities to respect Syria’s sovereignty and prevent foreign gunmen from crossing the border to fight in the civil war.

The Coalition has no control over the mosaic of armed rebel groups fighting on the ground insideSyria, and it was unclear what impact, if any, Sabra’s appeal would have.

However, an amateur video released by the Aleppo Media Center showed what it said were dozens of members of the Tawheed Brigade in the northern city of Aleppo who were said to be heading to Qusair to help the rebels. The rebels were driving pickup trucks, cars and trucks, some of them mounted with anti-aircraft guns.

Opposition fighters in Qusair were holding out Wednesday, but appeared to be under increasing strain as government tanks and artillery pounded the town and warplanes bombed it from the sky.