Five guards were killed at Yemen's presidential palace and a ministersurvived an ambush attack Friday, after the government warned Al-Qaeda wouldretaliate for an offensive aimed at crushing it.President Abdrabuh Mansur Hadi was not at the palace located in the capital Sanaawhen suspected Al-Qaeda gunmen attacked a checkpoint outside the compoundmanned by guards, killing five of them and capturing others, a security source told AFP.An exchange of fire broke out and went on for more than 20 minutes, according toother security sources and witnesses, amid reports that three of the assailants werekilled.Also on Friday, Yemen's defence minister, Mohamed Nasser Ahmad, and two seniorsecurity officers escaped unharmed when Al-Qaeda militants ambushed their convoyas they returned from a tour of the south where the army is battling the jihadists.The ambush came hours after the defence minister vowed in a statement to crushAl-Qaeda fighters in Yemen, saying their end would come soon.The army launched a major offensive on April 29 against Al-Qaeda in the ArabianPeninsula (AQAP) strongholds in three provinces, two in the south and one in thecentre, and claims it has inflicted heavy losses on the jihadists.Sanaa has been on alert for days and tensions rose after the army announced troophad entered Azzan, a jihadist bastion in southern Shabwa province, prompting theclosure of the US embassy Thursday.That night security forces killed Al-Qaeda commander Shayef Mohammed Said al-Shabwani, one of the jihadist network's most wanted leaders suspected ofmasterminding the abduction of Western diplomats.He was killed in an gunfight near the presidential palace after resisting arrest at acheckpoint. Another suspect was killed and three more were arrested, two of whomwere wounded, a source said.Authorities say Al-Qaeda commanders were among dozens of jihadists killed sincethe army launched its offensive 11 days ago in the south, where US drone strikesthis year have killed scores.AQAP is regarded by Washington as Al-Qaeda's most dangerous franchise and hasbeen linked to failed terror plots in the United States.- 'Desperate acts' -On Monday the interior ministry warned that "huge losses" in jihadist ranks "willpush Al-Qaeda to commit hysterical and desperate acts."State media also said on Friday that Yemeni security forces had killed two foreignAl-Qaeda fighters -- a Saudi and a Dagestani -- and captured two French citizens ofTunisian origin also belonging to the group.Earlier a bomb in a bus wounded 11 policemen in an eastern district of the capitalwhere the British and Qatari embassies are located, the day after assailants openedfire on guards outside the Saudi diplomatic mission.In other violence on Friday, the army said six suspected jihadists were killed inclashes in central Baida province.In Shabwa province, officials said security forces killed an explosives expert fromRussia's Dagestan and a "terrorist" from Saudi Arabia, without saying when. And two French jihadists of Tunisian origin were arrested on Thursday as they triedto flee Yemen from an unidentified airport, Saba said.Gunmen on Monday killed a Frenchman in Sanaa and wounded another when they opened fire on their car. The pair worked for a private security company thatofficials said was guarding the European Union delegationThe jihadists took advantage of an Arab Spring-inspired uprising that forcedautocratic president Ali Abdullah Saleh from power to seize large swathes ofsouthern and eastern Yemen.The army recaptured several major towns in 2012 but has struggled to reassertcontrol in rural areas, despite the backing of militiamen recruited from tribes.On Wednesday, a State Department spokeswoman said the US embassy in Sanaa would be temporarily closed to the public "due to recent attacks against Westerninterests in Yemen".The embassy closed in August along with other Western missions after US warningsof an Al-Qaeda attack.AQAP leader Nasser al-Wuhayshi vowed, in a rare video appearance last month, toattack Western "crusaders" wherever they are.Al-Qaeda uses the term crusaders to refer to Western powers, especially those whichhave intervened militarily in Muslim countries, such as Britain, France and theUnited States.