Fierce clashes between the army troops assisted by tribal militias and al-Qaeda linked gunmen continued on Wednesday morning in the southern Yemeni province of Abyan, leaving at least 20 militants and 7 soldiers killed, according to local sources.Sources said that fierce clashes erupted in the early hours of Wednesday morning between the two warning sides in the outskirts of Ja'ar town, the second biggest city in Abyan and al-Qaeda stronghold. The army has been imposing siege on Ja'ar as a part of an effort to push the militants out.Military operations intensified at the behest of President Abdu Rabu Mansour Hadi who ordered the troops to storm the al-Qaeda-controlled towns and kick the militants out of them.According to the sources, al-Qaeda carried out a counter attack on military troops stationed around Ja'ar but the army troops and the tribesmen managed to repel the attack, and kill 20 militants. After the foiled al-Qaeda attack, the army troops have tightened their siege on the militants. Meanwhile, the local news website said government troops from 135 and 201 Brigades managed to foil some militants' attempts to infiltrate into army positions.Ansar al-Sharia infiltrated into some army outposts in the past few months, killing dozens soldiers and wounding dozens of others.