German President Frank-Walter Steinmeier is to attend a minute's silence in memory of murdered police officer Rouven Laur at 11:34 am (0934 GMT) in the market square of the south-western city of Mannheim on Friday.
Premier Winfried Kretschmann of the state of Baden-Württemberg, where Mannheim is located, and the state's Interior Minister Thomas Strobl are also expected to be there.
One week after the fatal knife attack on the market square, the German president plans to lay a bouquet of flowers at the scene of the crime.
At 6 pm, the far-right Alternative for Germany (AfD) party plans to demonstrate on the square against Islamism. A counter-demonstration by thw anti-fascist organization Antifa is to take place at the same time.
Last Friday, a 25-year-old Afghan injured five participants at a rally organized by the anti-Islam movement Pax Europa as well as a police officer with a knife. The 29-year-old officer later died of his injuries.
At 4:30 pm, a rally is planned under the motto "Mannheim stands together - for democracy and diversity," organized by the local branch of the German Trade Union Federation and representatives of democratic parties and religious communities.
A demonstration against the AfD rally is planned at 5:30 pm by the "Mannheim against the Right" alliance.
On Thursday, the Karlsruhe Administrative Court granted an urgent appeal by the AfD against a general order by the city which banned events such as demonstrations on the market square.
On Tuesday, the city had temporarily declared the market square a memorial site for the dead police officer and banned events such as demonstrations.