United Nations: UN Secretary General Ban Ki-moon on Friday strongly condemned terrorist attacks on two mosques in Yemen\'s capital Sanaa and called on \"all Yemeni sides to immediately cease all hostile actions and exercise maximum restraint\".

\"The secretary general strongly condemns the terrorist attacks on two mosques during Friday prayers in Sanaa, as well as on a government building and mosque in Sadah, which have killed and wounded dozens of people,\" deputy UN spokesperson Farhan Haq was quoted as saying by Xinhua.

\"He deplores the killing of civilians and extends his condolences to the families of the victims,\" Haq added.

Ban demanded that all sides must abide by their stated commitments to resolve differences by peaceful means. He called for their engagement in the ongoing UN-facilitated negotiations in order to reach a consensus agreement in accordance with the Gulf Cooperation Council Initiative and Implementation Mechanism, outcomes of the National Dialogue Conference and the Peace and National Partnership Agreement.

He also reminded all Yemeni parties of their obligations under relevant Security Council resolutions.

\"The secretary general urges all to remain fully engaged with his special adviser on Yemen so as to enable him to continue to exercise the secretary general\'s good offices in close cooperation with the members of the GCC and the Security Council,\" said Haq.

Two suicide bombers attacked two mosques in Yemen\'s capital of Sanaa during Friday prayers, killing more than 135 people and wounding many others, media reports said, adding that the attacks raised fears that the Arab country is slipping into a sectarian war.

This is the second bombing attack in Sanaa this year after an Al Qaeda car bombing attack against the police academy killed at least 50 cadets on January 7.

The bombers detonated explosives at the two mosques controlled by the Shia Houthi group, the reports said, adding that most of the dead were supporters of the Houthi group.

The Shia Houthi group took over control of Sanaa in September and met strong resistance in the central and southern regions by powerful Sunni tribes and Sunni-dominated Al Qaeda network.

On Thursday, tribal militia fought against security forces supported by the Houthi group in the southern port city of Aden, the second biggest city in the country, killing at least 15 people.

UN chief slams deadly terrorist attacks in Yemen