AN attempted parcel bomb plot originating in Yemen will further heighten security concerns about the unstable Arab state, seen by the West as the home of Al-Qaeda's most inventive and audacious affiliate. A series of brazen attempted attacks on Western and Arab targets have been launched over the past 18 months by Al-Qaeda in the Arabian Peninsula (AQAP), headed by Nasser Al-Wahayshi, a Yemeni former associate of Osama Bin Laden. President Barack Obama said Friday security officials in Britain and Dubai had intercepted parcel bombs being sent from Yemen to the United States in a “credible terrorist threat.” He said the parcels were bound for “two places of Jewish worship in Chicago.” There was no immediate claim of responsibility. But Obama said US officials suspected AQAP, fighting to try and topple the Yemen government, was behind the two suspicious packages. The group's actions have earned it a reputation as the most aggressive arm of Al-Qaeda's globally-scattered hubs of sympathizers and affiliate groups. The group claimed responsibility for a Dec. 25 2009 failed attempt by a Nigerian militant to down an airliner over Detroit. The device, hidden in the underwear of the man, Umar Farouk Abdulmutallab, failed to detonate. Abdulmutallab had visited Yemen and had been in contact with militants there. The same year, Al-Qaeda carried out a suicide attack that killed four South Korean tourists in Yemen. This year it has repeatedly targeted Yemeni security officials. But it is not only militant attacks that have won AQAP notoriety. It is also an energetic producer of Al-Qaeda propaganda and the publisher of the group's ambitious English-language magazine Inspire, which has surprised many with its slick, teen-magazine style presentation. And it plays host to Al-Qaeda's most gifted English language propagandist, Anwar Al-Awlaki, an American militant preacher of Yemeni ancestry who argues effectively using Western idioms and ideas, a rare talent in Al- Qaeda ranks. Awlaki and his fellow contributors to Inspire are the most prominent examples of a new wave of English-language commentators influencing some young Western-based Muslims. Awlaki was the only Al-Qaeda leader named by British Secret Intelligence Service chief John Sawers when he outlined threats to the UK Thursday in the first ever speech by a serving head of the country's overseas espionage agency. US officials are worried about the emergence of so-called homegrown militants in the United States who apparently radicalize themselves by visiting Internet sites that host strongly anti-Western commentary written in English. US officials have said Washington has authorized the CIA to kill or capture Awlaki. AQAP has threatened the United States with more attacks should he be harmed. AQAP is one of several Al-Qaeda offshoots that have sprung up in the past three years and are trying to attract militants from the West to their ranks, apparently encouraged by Al-Qaeda leader Osama Bin Laden. Under pressure from drones, the militant leader of Yemeni ancestry has hit upon a strategy of smaller, more easily-organized attacks, carried out by offshoots far from the Afghan-Pakistan border area where he is believed to be hiding. The head of Britain's MI5 security service said on Sept. 17 that suspected Al-Qaeda plots targeting Britain originate increasingly in Somalia and Yemen, partly as a result of counter-terrorism pressure on the group's leaders in Pakistan. “There is a real risk that one of his (Awlaki's) adherents will respond to his urging to violence and mount an attack in the UK, possibly acting alone and with little formal training,” Jonathan Evans said.