SANAA, Yemen (AP) - Under a heavy fog, al-Qaida militants disguised in military uniforms launched car bomb attacks on three different security and military posts in southern Yemen on Friday, killing 38 soldiers in the group's biggest attack in the country since last year. The coordinated attacks point to how al-Qaida is exploiting the continued weakness of Yemen's military to rally back here at a time when the group's branches across the region grow more assertive. More than two years after U.S. raid that killed Osama bin Laden, factions of the group he led are taking advantage of turmoil in multiple Arab nations to expand their presence and influence. In Syria, foreign jihadis linked to or inspired by al-Qaida have become such a powerful force in the rebellion that the Syrian opposition on Friday accused them of being opportunists hijacking the uprising against President Bashar Assad. After the coup in Egypt toppled the Islamist president, al-Qaida leaders have called on sympathizers to join militants' fight there against the military. Iraq's al-Qaida branch has stepped up attacks in that country and extended operations into neighboring Syria. Last month, the U.S. temporarily closed 19 diplomatic missions across the Middle East and North Africa after intelligence agencies intercepted a message between al-Qaida leader Ayman al-Zawahri and Nasser al-Wahishi, also a one-time confidant of bin Laden who leads the Yemen branch, known as al-Qaida in the Arabian Peninsula. I think there's been a promiscuous rush to write al-Qaida's obituary, and it's always been presumptuous. It's certainly had setbacks ... but its resilience has always been more formidable than we imagine," said Bruce Hoffman, director of the Center for Security Studies at Georgetown University. Experts in extremist networks see no clear evidence of coordination between groups under the al-Qaida banner. But gains by one serve as powerful encouragement and recruiting tools for others. "What matters perhaps more is how they may draw inspiration from each other," said Theodore Karasik, a security and political affairs analyst at the Dubai-based Institute for Near East and Gulf Military Analysis. For a time, al-Qaida in the Arabian Peninsula was perhaps the most powerful of the terror group's branches in the region. It carried out a series of attempted attacks on U.S. soil - and Washington branded it one of the world's most dangerous terror groups. In 2011, with Yemen in political turmoil amid the uprising that eventually led to the removal of President Ali Abdullah Saleh, al-Qaida fighters seized control of a string of cities and towns in the south. It was beaten back in 2012 by a Yemeni military offensive supported by a heavy campaign of U.S. drone strikes. The assaults drove its fighters out of the southern strongholds and into hiding in mountainous regions, from which they harried the Yemeni military with attacks and assassinations. Near-daily U.S. drone attacks in the first week of August killed 34 suspected al-Qaida militants. Friday's attacks in the southern province of Shabwa, a one-time al-Qaida stronghold, showed the group's continued capabilities. Militants struck three security and military posts nearly simultaneously at 6 a.m. in an area near the Balhaf liquefied gas export terminal on the Arabian Sea coast, said Maj. Nasser Mohammed, who is with a unit in the area. Two military officials said 38 police and soldiers were killed. Militants were dressed up in military uniforms and drove cars with army license plates, one military official said. They struck at the transition between guard shifts, catching them by surprise, indicating they had information on the force's work schedules, the official said. Both spoke on condition of anonymity because they were not authorized to talk to the press. In the deadliest attack, a suicide car bomber rammed his explosives-laden vehicle into the Interior Ministry's al-Kamp Central Security camp in the area al-Mayfaa, causing most of the deaths. Clashes at another site in al-Mayfaa left at least five troops wounded, Nasser added. Meanwhile, a car bomb was detonated prematurely outside the gates of the third site, the post in al-Ain. The blast was followed by heavy clashes during which militants seized six soldiers and a number of military vehicles. Yemen's Supreme Security Committee, headed by the president, issued a statement listing 10 al-Qaida militants as top perpetrators of the attacks and vowed to bring "criminal, coward and terrorist elements to justice." Part of Yemen's woes is the divisions within army ranks. Since Saleh's removal, President Abed Rabbo Mansour Hadi has vowed to restructure the military, removing Saleh's relatives in the Republican Guard forces and other key units in the military. But he has so far failed to carry out broader reforms purging Saleh loyalists from the military and other government posts, a move experts say is needed to improve the armed forces sand security. Sanaa-based researcher in Islamic movements, Ziad al-Salami, said Yemen needs to speed up reforms, saying Friday's attacks were a "strong message" - "Al-Qaida is trying to show that it still carries weight on the ground." Al-Qaida militants are now present in four major Yemeni provinces - Shabwa, Abyan, Hadramawt and Jouf, bordering Saudi Arabia, he said. This belt is a strategic one because it's the region where oil is concentrated, and where Yemen has a long coastal line. In Washington, Marie Harf, deputy spokeswoman for the U.S. State Department, condemned the attacks and said the U.S. supports "the efforts of the Yemeni government and its brave security forces in combating al-Qaida in the Arabian Peninsula." The surge of al-Qaida fighters in Yemen along with their increasing role in Syria's civil war raises the question of the role of the terror network's central leadership - al-Zawahri and his lieutenants - in coordinating the various branches. The leadership, based in the Afghanistan-Pakistan border regions, had been thought to be reeling after bin Laden's death and later blows. Hoffman, of Georgetown University, pointed to reports of al-Qaida central sending senior members to Syria and Yemen. "If the core is active overseas it's not as decimated in South Asia as we think," he said. There's a proclivity to count al-Qaida out (but) it can still send key cadres to critical theatres of operation. Foremost, al-Qaida has "hitched its fortunes to Syria," he said - since a stronghold there brings it close to the top U.S. allies in the region, Turkey, Jordan and Israel. In testimony Wednesday in Washington before a House subcommittee on counterterrorism and intelligence, analyst Katherine Zimmerman said there are "far-reaching" challenges in confronting the al-Qaida networks. "Operations specifically targeting a single group, including AQAP, would have a limited overall effect on the network," said Zimmerman of the American Enterprise Institute, a Washington-based conservative think tank. The lateral connections - relationships between al-Qaida groups - create a latticed structure that adds to the resiliency of the network.  AP Correspondents Maggie Michael in Cairo, Brian Murphy in Dubai, Adam Schreck in Baghdad and Raphael Satter in London contributed to this report.