ANKARA, Turkey — With less than 48 hours left in 2015, Turkey on Wednesday became the latest country to announce the foiling of a holiday attack plot, detaining two suspected Islamic State militants believed to be planning suicide bombings during New Year celebrations in the capital city’s heart.

“They were caught before they had the opportunity to take action,” said the office of the chief prosecutor of Ankara, Turkey’s capital.

The men were detained in a raid on a house in the low-income Mamak neighborhood, where police seized a suicide vest armed with a bomb, a second explosive device that was fortified with ball bearings and metal sticks and concealed inside a back pack, as well as bomb-making equipment, according to the prosecutor’s office.

The two men, Turkish nationals identified only by their initials M.C. and A.Y., were being questioned by anti-terrorism police. The prosecutor’s office said the men had staked out possible locations in Ankara where they could carry out the attacks.

The state-run Anadolu Agency, quoting unnamed police and judiciary officials, said the would-be bombers had intended to blow themselves up during holiday festivities at bars and a shopping mall in the central Kizilay district.

In Belgium, an investigation was continuing into what authorities characterized as a “serious threat” of holiday season attacks directed at police, soldiers and popular attractions in the capital city of Brussels. The arrest of two suspects was announced Tuesday by the Federal Prosecutor’s Office, along with the seizure of military-style training uniforms, computer equipment and propaganda materials from the Islamic State. No weapons or explosives were found.

Brussels officials, however, were sufficiently worried about the remaining risks that Mayor Yvane Mayeur announced Wednesday evening that a New Year’s Eve fireworks display and related festivities planned Thursday in the city center are being canceled.

Last year, Mayeur told RTBF French-language television, 100,000 people turned out, and in current circumstances, he said, “we can’t guarantee that we can check everyone.”

On Thursday, the arrested men, whose names have not been made public, are due to go before a magistrate, who will decide whether to hold them for another month. An official said both suspects belong to a motorcycle club, the Kamikaze Riders, which is known for illegal stunts.