Two deadly car bombs hit the capital Sanaa and a southern city in Yemen on Tuesday, state news agency Saba reported, a day after air strike and clashes killed almost 200 people nationwide.
Islamic State in Yemen claimed responsibility in a statement posted online for the Sanaa attack, latest in a string of recent actions by the hardline Sunni Muslim group against Shi'ite Houthis who run the capital.
One of the explosives-laden cars detonated near a hospital in downtown Sanaa, which the news agency controlled by Yemen's dominant Houthi group said killed and injured "numerous" people, while another killed around 10 people in al-Bayda, capital of a province in the country's battle-weary south.
Saudi-led coalition air strikes and clashes killed at least 176 fighters and civilians in Yemen on Monday, residents and media run by the Houthi movement said, the highest daily toll since the Arab air offensive began more than three months ago.
The United Nations has been pushing for a halt to air raids and intensified fighting that began on March 26. More than 3,000 people have been killed since then as the Arab coalition tries stop the Houthis spreading across the country from the north.
The Iran-allied Shi'ite Houthis say they are rebelling against a corrupt government, while local fighters say they are defending their homes from Houthi incursions. Sunni Saudi Arabia says it is bombing the Houthis to protect the Yemeni state.
As fighting has raged across Yemen's south, the conflict has taken on a sectarian tinge, pitting the Shi'ite Houthis against local Sunni fighters who in many places fight alongside hardline al Qaeda militants, who also revile the Houthis.
On Monday, about 63 people were killed in air strikes on Amran province in the north, among them 30 people at a market, Houthi-controlled state media agency Saba said.
In the same province, about 20 fighters and civilians were killed at a Houthi checkpoint outside the main city, also named Amran, about 50 km (30 miles) northwest of the Yemeni capital of Sanaa, local residents said.
Arab alliance war planes also killed about 60 people at a livestock market in the town of al-Foyoush in the south.
Also in the south, residents reported a further 30 killed in a raid they said apparently targeted a Houthi checkpoint on the main road between Aden and Lahj. They said 10 of the dead were Houthi fighters.
Tribal sources in the central desert province of Marib said about 20 Houthi fighters and soldiers fighting alongside them were killed in air raids and gun battles with tribal fighters, who support Yemen's president in exile Abd-Rabbu Mansour Hadi.
On Tuesday, U.N. envoy to Yemen Ismail Ould Cheikh Ahmed continues meetings with Houthi officials in Sanaa to try to broker a ceasefire to allow aid deliveries. One Houthi official said Monday's attacks had dealt a blow to peace efforts.