Warsaw, Aug 18 (DPA) Polish police detained a 60-year-old man Wednesday who was allegedly carrying a disarmed grenade near the presidential palace, local media reported.

The man was allegedly threatening people near the palace that were defending a cross placed there to commemorate president Lech Kaczynski, who was killed with 95 others in a plane crash in Russia in April. The man faces up to 10 years in prison if found guilty.

The incident comes amid growing controversy over whether the cross should stay at the palace or be moved to a nearby church.

City officials told TVN 24 that if the situation does not calm, they may increase security or close the street off to traffic.

Police detained another man Tuesday after he allegedly threw a jar of faeces at a plaque commemorating the plane crash victims. Newly-elected President Bronislaw Komorowski sought earlier this month to defuse the row over the cross by placing the plaque in a side wing.

But Kaczynski supporters criticised the move, saying they were not consulted and vowed to maintain their vigil outside the presidential palace until a permanent memorial was erected in place of the cross.

Supporters of Kaczynski have opposed government plans to remove the cross, which was placed there by scouts as a spontaneous gesture to mourn the plane crash victims.