Belgian police have arrested a man suspected of threatening to ritually kill a senator who criticised Muslims.
Mimount Bousakla has received police protection
Socialist senator Mimount Bousakla was put under police protection this week after receiving the death threats.
Three other senior politicians have also received death threats, but officials say the cases are not linked.
Meanwhile, Dutch prosecutors have called for a three-month jail sentence for a man who posted website death threats to politician Geert Wilders.
The right wing politician has said Islam is incompatible with democracy and called for new curbs on immigration particularly from Turkey and Morocco.
The prosecution was appealing an earlier court ruling which sentenced Farid Achahboun, 30, to 120 hours of community service and a month's suspended sentence.
He was arrested in October 2003 for posting messages on a website saying: "Wilders should really be punished with death for his fascist remarks about Islam, Muslims and the Palestinian cause."
The 38-year-old Belgian Muslim convert arrested in neighbouring Belgium on Thursday is reported to have admitted threatening Ms Bousakla.
The Antwerp senator appears to have been targeted after she said Belgium's umbrella group for Muslim organisations, the Muslim Executive, should have organised protests against the murder of the controversial Dutch filmmaker Theo Van Gogh, who was killed in Amsterdam by an alleged Islamic extremist on 2 November.
Ms Bousakla, 32, whose parents are Moroccan, came to prominence after writing a book about her cross-cultural upbringing called Couscous with Belgian Fries.
She has received sporadic death threats ever since, but this time they were taken so seriously that she went into hiding and was given round-the-clock police protection.
Police are also focusing their patrols on the Jewish area of Antwerp after a British Orthodox Jew, Moshe Yitzchak Naeh, 24 was shot dead on Thursday.
It is not yet clear whether the attack was racially-motivated but the authorities are not ruling out any lines of enquiry.
Belgian Justice Minister Laurette Onkelinx and former Justice Minister Philippe Moureaux were among other officials to have received death threats.
Racial tensions have been growing in Belgium, where the far-right Vlaams Blok party won a quarter of the votes in this summer's European elections.
The death of Mr Van Gogh has also highlighted a widening racial divide in the Netherlands, where far-right politicians are gaining ground.
His murder is thought to be connected to a film he made criticising Islam's treatment of women.