At least 10 Muslim worshippers performing Eid al-Adha prayers were killed yesterday when an Isil suicide bomber disguised as a woman blew himself up at a mosque run by Yemen's Houthi group, security sources said.
Isil's branch in Yemen said the attack at al-Balili mosque, just outside the Old City of Sanaa, had killed or wounded dozens of "rejectionists". The Sunni militant group uses that term to describe Shi'ite Muslims it deems to be heretics.
"In a security operation facilitated by God as part of the acts of revenge for Muslims from the rejectionist Houthis, brother Abu Omar al-Hadidi waded into a crowd of apostate Houthis at al-Balili temple, detonated his suicide belt causing dozens to perish or to be injured...," the statement said.
Medics said at least 36 other people were wounded. A Houthi website gave a death toll of at least 10, while Arab media said it was at least 25.
The Houthis, allies of Iran, seized Sanaa a year ago and forced President Abd-Rabbu Mansour Hadi into exile in Saudi Arabia.
Since March, the Western-allied Saudis have led an Arab coalition trying to restore Hadi to power and drive the Houthis back to their northern stronghold.
More than 4,500 people have been killed in the conflict, which Isil has exploited to expand its operations.
Witnesses had earlier described a twin suicide attack on the mosque.
Nayef, who lives nearby, said he heard one explosion followed quickly by a second. "We gathered to rescue the wounded. The situation is very painful and blood is everywhere."
The witnesses said the first blast shook the mosque soon after worshippers gathered for prayers. A second suicide bomber detonated his explosives belt when Houthi guards tried to stop him rushing deep inside the mosque.
"We rushed outside and summoned the ambulances," one witness said.
Houthi fighters sealed off the area and shouted at onlookers to stay away.
It was the second attack in the capital this month to target a mosque run by the Shi'ite Zaydi group. On September 2, at least 28 people were killed and 75 wounded in twin suicide bombings claimed by Isil at a mosque in northern Sanaa.
In March, Isil suicide bombers killed at least 137 worshippers and wounded hundreds more in coordinated attacks at two mosques during Friday prayers in Sanaa.
The explosions came amid more fighting between the Saudi-led alliance and Houthi fighters, backed by supporters of former President Ali Abdullah Saleh.
Saudi-owned al-Arabiya television said that at least 40 Houthis were killed while trying to sneak into a Saudi village across the border with Yemen.