Turkey and six Gulf Arab states condemned the attacks in Brussels on Tuesday that killed at least 26 people at the airport and aboard a metro train.
Both Prime Minister Ahmet Davutoglu and the spokesman of President Tayyip Erdogan strongly condemned the attacks, which came three days after a suspected Islamic State member blew himself up in Istanbul, killing four tourists.
The secretary general of the Gulf Cooperation Council (GCC), Abdullatif al-Zayani, said in a statement the GCC offered its support to Belgium. The bloc comprises Saudi Arabia, Kuwait, Bahrain, Oman, Qatar and the United Arab Emirates.
The blasts at the airport and metro station occurred four days after the arrest in Brussels of a suspected participant in November militant attacks in Paris that killed 130 people.