Germany's interior minister said on Friday Hamas supporters should be deported from the country where possible, and authorities would keep a close eye on potential threats following the Palestinian militant group's attack on Israel.

"If we are able to deport Hamas supporters, we must do this," Nancy Faeser said following talks with officials at the Federal Criminal Police Office.

"Our security authorities have currently placed an even stronger focus on the Islamist scene," she added, pointing to a recent attack in Brussels as an indication of the threat.

Concerns over antisemitism are growing in Germany, particularly following an attempted attack on a Berlin synagogue with petrol bombs, and clashes between pro-Palestinian protesters and police in Berlin and other cities.

At the same time members of Germany's large Palestinian community have said their voices are being silenced by demonstration bans.

Faeser appealed to citizens to alert authorities of any "propaganda" supporting Hamas.

On Friday, prosecutors in Munich searched the house of a 38-year-old German national over an Instagram post defending Hamas's attack, according to a statement from the prosecutor.

"We will not allow this vile hatred and horrific violence to spread," Faeser told reporters.