Washington, Brussels: The US on Wednesday denounced a deadly attack on the Iranian ambassador’s residence in Yemen’s capital, calling for a “thorough” investigation.

“The United States condemns the bombing at the Iranian ambassador’s residence in Sana’a earlier this morning [Wednesday] and expresses its condolences to the families of the victims,” State Department spokeswoman Marie Harf was quoted as saying in a statement.

Though the ambassador was not at his home when the bomb explosion occurred, media reports said, his house was damaged.

Three security guards — two Iranians and a Yemeni — were confirmed dead in the remote-controlled car bomb explosion which also left 17 people injured, some of them critically.

“Attacks on diplomatic facilities and against diplomats contravene all international norms and can never be justified or excused,” Harf said, urging the Yemeni authorities to open a “ thorough” investigation and “bring the perpetrators to justice”.

Al Qaida in the Arabian Peninsula (AQAP) claimed responsibility for the attack, saying it detonated a car bomb when the Iranian ambassador left his residence Wednesday morning.

In another sign of warming ties between Washington and former arch-foe Iran, US Secretary of State John Kerry on Wednesday welcomed any Iranian military action against Daesh militants in Iraq as “positive” after the Pentagon said Tehran had carried out air strikes against the group.

Kerry denied there was any military coordination with Iran after the Pentagon said that Iranian F-4 Phantom jets — acquired from the United States before the 1979 Islamic revolution — had deployed against Daesh fighters in Iraq’s eastern Diyala province.

He suggested, however, that there was an understanding between mainly Iran and the US to tackle a common threat.

“If Iran is taking on (Daesh militants) in some particular place ... and it has an impact, then it’s going to be net effect (that) is positive,” Kerry told a press conference after the meeting.

In Washington, US defence officials said the Iranian air raids were part of a pattern in which Iranian or American military advisers have carved out separate spheres in Iraq.

“There’s a tacit understanding we’re not going to operate in the same space. And they’re not targeting American forces,” a defence official, who spoke on condition of anonymity, said.

— with inputs from IANS and AFP