SANAA: At least 31 people were killed Wednesday and dozens wounded in five simultaneous bombings claimed by ISIS at Shiite mosques and offices in the Yemeni capital, medics and witnesses said.

The blasts rocked the capital as Saudi-led forces conducted more airstrikes against Houthi military bases across Yemen and delegates attending peace talks in Switzerland reported no progress on the second day of a U.N.-sponsored push for a Ramadan truce.

A security official said dozens more were wounded in the attacks on the Hashush Mosque, the Kibsi Mosque, the Al-Qubah al-Khadra Mosque and the political bureau of the Ansarullah movement of the Houthis, who belong to the Zaydi sect of Shiite Islam.

“The explosion was so loud I thought it was caused by an airstrike,” said a man in his 70s named Ali who had just left a mosque when a bomb went off.

“I returned and found cars burning, people screaming and wounded people all over.”

ISIS said in a statement posted online that it carried out the attacks.

“The soldiers of the Islamic State in Yemen, in a wave of military operations as revenge for the Muslims against the Houthi apostates, [detonated] four car bombs near the centers of Houthi apostasy,” it said, using the group’s latest name.

The attack is the most serious of its kind in Yemen since suicide bombers killed at least 137 worshippers and wounded hundreds during Friday prayers at two mosques in Sanaa on March 20, in attacks also claimed by ISIS.

The Houthi-controlled state news agency quoted an official blaming ISIS for the latest bombings. Supporters of ISIS exchanged celebratory messages on social media.

ISIS has recently stepped up its operations in Yemen, where Al-Qaeda in the Arabian Peninsula, also Sunni Islamist, had long dominated the militant scene.

AQAP recently suffered a serious blow when a U.S. drone strike killed its leader, Nasser al-Wuhayshi.

AQAP militants shot and killed two Saudis in public in the city of Mukalla Wednesday, after accusing them of placing tracking devices that helped guide the attack that killed Wuhayshi, residents said.

Earlier Wednesday Houthi fighters in central Yemen blew up the home of a senior politician, Abdel-Aziz Jubari, while he was attending the Geneva talks as a member of the exiled government’s delegation.

Yemen’s Foreign Minister Reyad Yassin Abdulla told Reuters in Geneva the peace talks had “made no progress.”

Residents of Dhamar city said the Houthis, who had taken over Jubari’s house in April, dynamited the building early in the morning. Yemeni websites published pictures of its collapsed roof on a pile of rubble.

Jubari, who is deputy head of the delegation sent to Geneva by ousted President Abed Rabbou Mansour Hadi, said he was shocked when he heard the news. “This is regrettable that people’s manners and behaviors can reach this point,” Jubari told Reuters in Geneva.

“Of course my house is not the only house in Yemen ... A lot of people’s homes and properties have been targeted in an unbelievable way.”

Abdulla, the head of the government delegation, said: “It is in this spirit of revenge that they are dealing with all the Yemeni people and we cannot remain silent on this.”

Houthi officials were not immediately available to comment.

The Houthis seized Sanaa in September and pressed into the country’s center and south, forcing Hadi and his government into exile in Riyadh. They say they are campaigning against corruption and years of political marginalization.A coalition of Arab states headed by Saudi Arabia has been bombing the Houthis and their Yemeni army allies since March 26. Their aim is to restore Hadi to power and head off what they see as Shiite Iran’s expansion in the region. The Houthis deny receiving military backing from Iran.

More than 2,600 civilians and combatants have been killed since March and a humanitarian crisis is looming as supplies of food, medicine and other goods run short.

The latest air raids by the Saudi-led alliance focused on army bases in Sanaa and Houthi targets in Yemen’s central desert and the mountainous province of Mahweet.

In Geneva, the U.N.’s special envoy to Yemen, Ismail Ould Cheikh Ahmed, has been conducting shuttle diplomacy between the two sides.

Early Wednesday Abdulla played down the prospects of a quick cease-fire deal, saying his team still wanted the implementation of a U.N. Security Council resolution demanding the Houthis quit cities they have seized since September. He said he did not want a truce merely “for the sake of publicity.”

Ould Cheikh Ahmed, who has asked the Houthi party to pick 10 of their number to represent them at the Geneva talks, said that he remained optimistic. But Abdulla said the Houthis had not formed their negotiating team by early evening.

In a speech Tuesday, Houthi leader Abdel-Malek al-Houthi held out hope for a resolution but accused his Yemeni opponents of seeking to advance Saudi Arabia’s agenda.

“There is nothing hindering a political solution in the country; the solution is available, but they [the Saudis] are the ones who ruin it with their aggression,” he said.