Yemen's army has suffered its most humiliating defeat yet at the hands of Islamic extremists who launched a sophisticated attack on an army base in the south on Sunday, resulting in the deaths of 90 soldiers.
More alarming still, the militants of the Ansar al-Sharia group, which is allied with al Qaeda in the Arabian Peninsula (AQAP), seized large amounts of weaponry. And they appeared to have had help from within the security apparatus in planning their operation, according to Yemeni officials contacted by CNN.
The attack took place near Zinjibar, a town on the Arabian Sea where Ansar al-Sharia has been active for nearly a year. One Yemeni official, who declined to be identified because he was not authorized to speak to the media, said militants began attacking an army base from the east, drawing the fire of troops, and then began attacking from the other side of the base. The "reinforcement response was too slow," he said, add that was partly because of sandstorms in the area.
One senior security official told CNN: "Troops were basically slaughtered by the militants. The attacks happened so suddenly; and this time they were more organized than we expected."
Officials say the Ansar al-Sharia fighters seized rocket launchers, mortars, armored vehicles, machine guns and even 13 tanks. Several of those tanks were later destroyed in an air strike by Yemeni jets.
Yemeni officials say the death toll is expected to rise; and at least 55 soldiers were captured by the militants. Some 25 militants were also killed in the clashes, they said.
Al Qaeda and Ansar al-Sharia have taken advantage of the power struggle that divided the military in the last year of President Ali Abdullah Saleh's rule. In May last year, Ansar al-Sharia fighters overran Zinjibar and have controlled much of the town ever since.
One Yemeni official told CNN that Sunday's attack "was a clear example why the division of the armed forces is bad. I think the divisions in the command of the armed forces is a factor in what happened" on Sunday, he said.
Those divisions were aggravated by the dismissal of Mahdi Makwalah, the military commander of the southern region, last week. He was one of several officials fired by Yemen's new President, Abdurabu Hadi.
On Sunday, several security officials alleged that Makwalah had handed over artillery to al Qaeda fighters. But in an interview with CNN Monday, Makwalah denied the military had been infiltrated by Ansar al-Sharia.
"Our troops are loyal to the country and there is no proof for such accusations," Makwalah said.
"The number of militants is growing in Abyan," Makwalah said. "Every day there are more fighters" and the military units in the area need reinforcement, he said.
Hadi vowed on Monday to continue the fight against al Qaeda until it is uprooted from the country.
"The president is serious on combating al Qaeda. He knows the dangers they possess and will not stop until they are defeated," said presidential spokesman Yahya al-Arassi.
Counter-terrorism and special forces have been dispatched to Aden and Yemeni officials say a major operation is underway against militant strongholds in Zinjibar and the town of Ja'ar, some 10 miles to the north.
"We will only escalate in our stance until the province is free from militants," said Ali Obaid, spokesman for the Yemen Military Committee.
The United States reacted with concern to the weekend's events
"We view Yemen as a very important partner on counter-terrorism efforts and we're also very concerned about the clashes that have taken place there, to include AQAP advances in certain parts in the country," said Defense Department spokesman George Little.
"The Yemeni government has faced challenges in certain parts of the country for some time so I wouldn't necessarily read anything at this point into the stability of the Yemeni government," he said.
Saleh gave up his presidential powers in November and Hadi, his Vice-President, was formally elected to succeed him on February 21. In his inauguration speech, Hadi said all Yemenis had a duty to confront al Qaeda. Hours later, militants attacked a Presidential mansion in the east of the country, killing 26 people.
There have also been bomb attacks against security services compounds in Hadramaut in the mountainous east of the country. Intelligence officers have been ambushed and killed or abducted. And a police chief in Aden, the main city in the south and an important seaport, survived an assassination attempt Monday. His bodyguard was killed.
The United States has been working to assist Yemen's security forces in the south. A vehicle carrying a U.S. security assistance team was fired upon last week in Aden, but the Defense Department said no one was hurt.
Hadi had been vice president for 18 years but analysts say he lacks his own power base among Yemen's major tribes and faces overlapping security, economic and humanitarian crises. One Yemeni official told CNN the most pressing need was for stability, but that was still lacking, even in the capital, Sanaa.