People gather to mark the 74th anniversary of the outbreak of the 1944 Warsaw Uprising against the Germans during the World War II, in Warsaw, Poland, on Aug. 1, 2018. The Warsaw Uprising broke out on Aug. 1, 1944 and was the biggest resistance operation in German-occupied Europe. (Xinhua/Jaap Arriens)

WARSAW, Aug. 1 (Xinhua) -- Poland on Wednesday marked the 74th anniversary of the Warsaw Uprising, the biggest underground action against the Nazi German in occupied Europe.

The main ceremonies in Poland's capital Warsaw were attended by top officials, veterans and residents. A wreath-laying ceremony at the plaque commemorating the signing of an order to start the Warsaw Uprising, attended by Polish President Andrzej Duda and Prime Minister Mateusz Morawiecki, opened the commemorative events in Warsaw.

"We remember that and we pay tribute today not only to those who fought in the Warsaw Uprising, but also to those who suffered in that uprising, who during the course of the uprising and after it were killed inhumanely by the Germans just because they were Poles," Duda said during the events.

Morawiecki pledged to double the financial support for surviving Warsaw insurgents. The prime minister also announced plans to create a list of graves of Warsaw insurgents and underground fighters in order to extend special state protection over those burial sites.

Sirens sounded throughout the city at 5 p.m. local time, the exact time of the Aug. 1, 1944 outbreak of the Warsaw Uprising against the Nazi occupants, to mark the insurrection's 74th anniversary.

As the sirens continued, traffic stopped throughout the city for a minute's silence to pay a tribute to the uprising's fighters and civilian victims.

The Warsaw Uprising was one of the biggest resistance operations in German-occupied Europe. Initially intended to last several days, it continued for over two months before it was brutally suppressed by the Nazi Germans. The uprising claimed the lives of 18,000 insurgents and around 200,000 civilians.

After the insurgents surrendered and the remaining 500,000 residents were expelled from the city, the Nazis methodically burned down and blew up Warsaw house by house. By January 1945, about 90 percent of the buildings and city infrastructure were destroyed.