ZAGREB, Croatia (AP) — Croatia on Sunday celebrated a 1995 military offensive in which its troops retook territory held by rebel Serbs, while Serbia’s president compared the attack known as Operation Storm to the policies of Nazi Germany.

Top officials attended a ceremony in the former rebel stronghold of Knin to mark the victory’s anniversary, hailing the offensive as a flawless military action that ended Croatia’s war for independence and reunited its lands.

U.S. and Israeli military envoys were among the guests attending the event, while Israeli jets joined Croat air forces in a fly-by, Croatia’s defense ministry said.

“(Storm) has become a textbook successful military operation,” Croatian President Kolinda Grabar-Kitarovic said. “It was the time of total unity of the Croatian people and Croatian soldiers.”

Meanwhile, neighboring Serbia mourned the hundreds of victims who were killed during the August 1995 attack. Serbian President Aleksandar Vucic accused Croatia late Saturday of intentionally expelling Serbs from the country because of their ethnicity.

Vucic’s comments whipped up tensions between two main Balkan rivals whose conflicting views illustrate the persistent divisions stemming from the 1991-95 war.

The war in Croatia erupted when the country declared independence from the former Yugoslavia. Minority Serbs in Croatia, backed by Serbia, took up arms and formed their own self-declared state, rejecting the split from the Serb-led Yugoslav federation and expelling hundreds of thousands of Croats from their homes.

More than 10,000 people were killed and many Croatian towns were devastated in the years that followed before Croatia reclaimed control of the Serb-held lands. The Croat blitz sent 200,000 minority Serbs fleeing the country in miles-long columns of tractors, cars and horse-driven carts.

In his remarks on Operation Storm, Vucic, who was an extreme Serb nationalist during the war, evoked the fate of Anne Frank, the Jewish diarist who died at the Bergen-Belsen concentration camp. The teenage Holocaust victim was persecuted for the same reason as the Croatian Serbs, the Serbian president said.

“The intent was the same. Hitler wanted a world without Jews; Croatia and its policy wanted a Croatia without Serbs,” Vucic told thousands at a commemoration event in northern Serbia.

Croatian officials rejected Vucic’s analogy.

“This is really too much,” Prime Minister Andrej Plenkovic was quoted as saying by Croatian public broadcaster HRT.

Croatian Defense Minister Damir Krsticevic also responded.

“We didn’t start the war. We defended ourselves and later liberated Croatia,” Krsticevic said.

The liberal Index news portal described the Serbian president’s statement as “scandalous” and asked if Vucic should be barred from entering Croatia.

Vucic has said he wants to boost cooperation with other Balkan nations and lead Serbia toward membership in the European Union, but he also has been increasing military and other ties with Russia.