Islamic State militants claimed responsibility for a wave of bombings Monday that killed at least 42 people in southern Yemen.
The blasts targeted security forces in the port city of Mukalla and happened around sunset as the soldiers were breaking their fast for the Muslim holy month of Ramadan.
Mukalla was under the control of al-Qaida fighters until April when pro-government forces recaptured it.
Yemen's years of instability, including the current conflict between the government and Houthi rebels, have allowed militant groups to control parts of the country and carry out attacks.
The United Nations is leading peace talks with the goal of creating a new unity government that can re-establish control in Yemen, but so far there has been no agreement.
U.N. Secretary-General Ban Ki-moon met with the government and Houthi delegations on Sunday and urged them to "prevent further deterioration of the situation."
His envoy for Yemen, Ismail Ould Cheikh Ahmed, said last week that there has been slow progress during the past two months, but that every day without a deal "needlessly extends the country's agony."