Prague - Gunter Demnig kneels on Prague's poshest shopping street, tapping a shining block into the cobblestone pavement beside a luxury-watch store.

"Here lived Eva Abelesova, born 1930, deported to Lodz in 1941 and murdered," reads the inscription under the Neo-Renaissance residential building at 10, Parizska Avenue.

In all, the German sculptor this week placed 10 such memorial cubes, which he calls stumbling blocks (Stolpersteine) in German, into the Prague streetscape, his first batch in the Czech Republic.

He brought them in his red van from Germany, equipped for the task with buckets of cobbling necessities: rubber-padded hammer, cement and sand.

"Eighty per cent of owners do not want to have a plate on their house," Demnig said. "This belongs to the city. I think it is better."

Demnig, who was born two years after World War II, began honouring victims of Nazi purges with 10-by-10-centimetre concrete blocks affixed with an inscribed brass plate in 1993.

He had no particular personal reason. He said there were neither victims nor culprits in his family.

Since then, he has placed over 16,000 of them, sponsored by surviving relatives or institutional donors, mostly across Germany as well as dozens in Austria and Hungary.

This week's Central European tour also includes the Czech town of Kolin, and the Polish city of Wroclaw. And his project is spreading to France, Norway and Ukraine, he explained.

"I have to keep going because there is so much interest," said Demnig, wearing a blue-jeans shirt and Australian-bush-style leather hat. His schedule is packed until mid 2009.

The stumbling blocks, popping up like golden teeth from sea of grey sidewalks, have caught the eye of 23-year-old Bianca Lipanska, born to Czech exiles in Hamburg.

She told fellow members of the Czech Union of Jewish Youth about the project, and the group set out to bring it to Prague, which was home to one of the Europe's oldest and largest Jewish communities before the Holocaust.

The city's Jewish population, some 40,000 before the war is under 1,600 today.

But the stumbling blocks, many of which were dedicated to other persecuted minorities, have also met with resistance.

The city councils of Munich in Germany, and Poland's Bydgosz have turned them down. While such cities usually cite technical problems, the project's supporters suspect them of hushing up the painful past.

Critics have bashed Demnig for degrading the victims by placing the memorials on the ground. His answer is simple - and humbling: "You have to bow when you want to have a look at a block." (dpa)