Iran’s foreign minister has cancelled a visit with his Austrian counterpart to show displeasure after the country had flown the Israeli flag in Vienna in a show of solidarity, the Austrian foreign ministry said on Saturday.

Iranian Foreign Minister Mohammad Javad Zarif was supposed to meet Alexander Schallenberg but had called off the trip, a spokeswoman for Schallenberg said, confirming a report in newspaper Die Presse.

“We regret this and take note of it, but for us it is as clear as day that when Hamas fires more than 2,000 rockets at civilian targets in Israel then we will not remain silent,” the spokeswoman said.

Israel has pummelled Gaza with air strikes and Palestinian militants have retaliated with rockets at Israel in the worst escalation of violence in years. 

Over 130 Palestinians have been killed in the Israeli strikes.