BEIRUT, Lebanon — The Syrian government’s retaking of a town this weekend that had teetered beyond its control is sharpening sectarian tensions along one of the country’s most explosive fault lines: relations between the Sunni Muslim majority and the minority Alawite sect to which the family of President Bashar al-Assad belongs, residents and officials say.

Each side offered a litany of complaints about the other, according to interviews with refugees, residents and activists, suggesting, even in a small sample, deepening animosities in a country where the fear of civil war is at once real and used as a pretext for suppressing dissent. Syria is a volatile blend of Sunnis, Alawites, Christians, Kurds and others inhabiting the same land, but with disproportionate political power vested in the Alawite elite.

Jisr al-Shoughour, where the government used tanks and helicopters to crush what it called “armed terrorist gangs,” sits in a landscape as complicated as anywhere in Syria. It is a Sunni town with an Alawite town less than a mile to the south, interspersed with Christian and more Sunni settlements.

One Sunni resident of Jisr al-Shoughour said he received a text message from an Alawite friend asking if his family was O.K. “I replied, ‘My two sisters with a baby have been killed,’ ” said the resident, who gave his name as Mohammed. Others accused Alawite neighbors of taking part in the crackdown, some coming from a town less than a mile away.