BAGHDAD — The international police organization Interpol stepped squarely into a bitter political and sectarian fight on Tuesday when it responded to a request for help from Iraq to arrest the country’s fugitive Sunni vice president on charges that he ran death squads inside Iraq.

The move is likely to add tensions to relations between Iraq’s Shiite leadership and leaders in Turkey, where the vice president, Tariq al-Hashimi, has been staying apparently with the blessing of the Turkish government since he fled his refuge in northern Iraq last month.

The Iraqi authorities want Mr. Hashimi returned to Baghdad, where judges are waiting to prosecute him on terrorism charges in what could be one of Iraq’s most politically charged court proceedings since Saddam Hussein’s trial about six years ago.

Iraqi authorities unveiled a litany of accusations and an arrest warrant against Mr. Hashimi late last year, just a day after the last American soldiers withdrew from Iraq, touching off a destabilizing political crisis between Prime Minister Nuri Kamal al-Maliki and his political opponents from Iraq’s Sunni minority. Those tensions have eased somewhat, but Mr. Hashimi’s case is still an open wound in political circles here.