A suicide car bomb on Monday targeted a house used by Shiite Houthi rebels in a town south of Sanaa, killing at least 10 and injuring 15, security officials said, in an attack that bore all the hallmarks of Al Qaeda.
The officials said the bombing in the Radaa area in Baydah province hit the house of Abdullah Idris, a top local official with the party of ousted President Ali Abdullah Saleh.
All victims were members of the Houthi movement, whose fighters overran the capital of Sanaa last month. The Houthis have since made significant military advances widely suspected to have been made with the help of Saleh's loyalists among tribes and in the military.
The officials spoke on condition of anonymity because they were not authorized to speak to the media.
No one claimed responsibility for the bombing, which took place just hours after the officials reported that fighting resumed between the Houthis and Al Qaeda fighters in Radaa. The battles left 13 of the rebels and 15 militants dead, according to tribal officials in the area.
Also on Monday, the officials said Al Qaeda militants captured the town of al-Adeen, 125 miles south of from Sanaa in Ibb province. They did not give details on the capture of the town, where gunmen from Al Qaeda last week stormed the local security headquarters and held it for hours before fleeing to the mountains.
The Houthis, widely suspected of links to mostly Shiite Iran, have been trying to take full control of Ibb since last week.
The fighting and the bombing in Radaa signal a widening battle between the Shiite rebels and the Sunni militants of Al Qaeda in a burgeoning conflict that threatens to evolve into a sectarian split similar to that in Syria and Iraq.
Al Qaeda last month appealed to Yemen's Sunni majority to rise up against the Houthis, who in turn have sought to portray themselves as fighting against terrorism while seeking to create a united Yemen. Al Qaeda claimed responsibility for a suicide bombing earlier this month that killed 51 people, mostly Houthis, in Sanaa as they headed to an anti-government rally.
The Houthi-Al Qaeda conflict is playing out against a backdrop of another layer of Yemen's woes: A growing secessionist movement in the once-independent south of the country.
Yemen has for years endured attacks by Al Qaeda on its army, security forces and state facilities while it struggled with crushing poverty that has bred resentment -- and outright rebellion. More recently, It has been grappling with a revolt by the Houthis who have in the past weeks overrun Sanaa and two northern provinces. Last week, they made another stunning sweep, taking control of the key Red Sea port city of Hodeida and the province of Damar south of the capital.
In Sanaa, the governor of Sanaa, Abdul-Ghani Jameel, resigned on Monday, days after the Houthis, who captured the capital last month, accused him of corruption and chased him out of his office.
The Associated Press contributed to this report.