Yemen unveiled a plot by al-Qaeda that aimed at targeting vital government establishments in the country, a statement by the interior ministry said on Thursday. “The plot is a desperate attempt by the terrorist group to respond to the severe blows that its operatives get in Abyan. It also comes after hundreds of militants have been killed and injured in the successful operation launched by the army and the security forces, with the help of Yemeni residents, against the terrorist group,” the statement said. The statement, published on the ministry’s official website, said that security measures have been tightened on all governmental buildings to face any possible threat. Earlier Thursday, Yemen’s army engaged in heavy gun battles with Islamist militants linked to al-Qaeda on the edge of the southern town of Jaar, part of a month-long offensive to retake several towns seized by rebels, local officials said. At least 20 Islamist fighters from Ansar al-Sharia (Partisans of Islamic Law), an offshoot of al-Qaeda, were killed, residents said. Five tribesmen fighting alongside government forces also died, the residents said. The Yemeni army is trying to recapture towns in the southern province of Abyan that were seized by the militants last year during a popular uprising against President Ali Abdullah Saleh, who formally stepped down in February. Residents said military helicopters took part in Thursday’s battles, bombing several rebel-held positions. The United States has become increasingly alarmed at the situation in Yemen which it views as being in the front line of its war on anti-American Islamist militants. In support of the army campaign, the United States has stepped up drone strikes against suspected militants. Concerned about the humanitarian and security crisis in Yemen, Gulf Arab states and the West pledged more than $4 billion in aid to the impoverished state last month. About 40 percent of Yemenis live on less than $2 a day. Aid agencies said in May almost half of them lack enough to eat.