United Nations Secretary-General Antonio Guterres said on Friday that the truth needed to be established after two oil tankers were attacked this week in the Gulf of Oman.

Guterres told reporters that the international body condemned the attack.

Ahmed Aboul Gheit, the head of the Arab League, urged Iran to reverse course, after the United States blamed the country for the attacks, Reuters reported.

Iran’s mission to the UN said earlier that Tehran categorically rejects the “unfounded” US claim over Thursday’s attacks on the oil tankers.