Updated

Yemeni warplanes and artillery strikes killed 20 al-Qaida-linked militants in heavy shelling and clashes on Wednesday in the country's south, according to Defense Ministry and military officials.

The ministry said an air raid targeted a militant communications station near the southern coastal town of Shaqra early Wednesday, killing three and wounding seven.

Military officials say the station was used by the militants to direct operations using the Internet, wireless communications and a satellite telephone.

Elsewhere, army shelling and clashes in the western the town of Jaar, an al-Qaida stronghold, left 17 fighters and six soldiers dead and injured 12 over the past 24 hours. The army is conducting an offensive against the town, which has been in al-Qaida's hands for more than a year.

The army "fought a fierce two-hour battles with terrorists," the statement said, adding that army engineers defused land mines planted by al-Qaida militants.

Residents who fled Jaar say that al-Qaida militants were using heavy weaponry, including tanks.

Mahdi Nasser, who fled Wednesday morning, said there has been constant shelling for two days, and most residents have fled in fear. He said he saw army positions four kilometers (2.5 miles) outside Jaar.

Officials said that over the past days, the military tried to advance toward Jaar but encountered fierce resistance.

Jaar is in Abyan province, where al-Qaida controls the provincial capital, Zinjibar.

The officials spoke on condition of anonymity in line with military regulations.

Backed by the U.S., Yemen's army is pursuing a wide offensive against al-Qaida in several parts of the south, after the militant group took control during a year of political turmoil that accompanied an uprising against longtime ruler Ali Abdullah Saleh.

Hitting back, a suicide bomber who blew himself up in the middle of a military parade rehearsal in the capital, Sanaa, on May 21, leaving nearly 100 dead. Al-Qaida claimed responsibility for the attack.