After weekly Friday prayers at Al-Mouminine mosque in the poor Belcourt district of Algiers, dozens of worshippers tried to march in the streets but were blocked by police, an AFP journalist reported.
"No to the Judaisation of Algeria!" and "Muslim Algeria!" were among slogans chanted by the demonstrators, who also condemned Israel's military offensive in Gaza.
They were responding to a call by Salafist leader Abdelfatah Hamadash to oppose the mooted reopening of synagogues, which he said would pave the way for "a normalisation of relations between Algeria and Israel".
The North African country's Jewish population, which numbered around 130 000 when a war of independence from France broke out in 1954, is tiny, although no official figures are available.
The vast majority left during the war, and those who remained were targeted by hardline Islamists during the bloody decade of civil strife, when two of their leaders were assassinated and synagogues closed.
Religious Affairs Minister Mohamed Aissa said last week that the Jewish community had "the right to exist," indicating its synagogues would eventually be reopened.
"There is a Jewish community in our country that is well accepted by Algerian society. It has the right to exist," he said, describing the community's leader as a "patriot".
He said, however, the reopening of synagogues was not likely soon, adding that "a place of worship must be made safe before it can be opened to the faithful".