SANAA, Yemen -- A suicide bomber attacked a crowd of police officers and cadets Wednesday afternoon at the entrance to a police academy in the Yemeni capital, killing at least 10 and wounding more than a dozen.

There was no immediate claim of responsibility for the attack, but suspicion fell on the Yemen-based group al Qaida in the Arabian Peninsula, which has a history of targeting Yemeni security forces. The attack came just over a month after an al Qaida-linked suicide bomber killed 90 soldiers at a parade ground a mile and half away from the police academy.

The attack underlined the continued threat that Yemen-based extremists pose despite a renewed military offensive by the new president, Abed Rabbo Mansour Hadi, that’s driven militants from several cities they’d held for more than a year. Hadi succeeded Ali Abdullah Saleh, whose three-decade rule ended after months of protests that weakened the central government’s already shaky grip and allowed al Qaida-linked militants, fighting under the banner of Ansar al Shariah, or Supporters of Islamic Law, to seize swaths of territory in the restive southern province of Abyan.

After Wednesday’s attack, pools of blood lay at the academy’s southern gate as police officers and cadets surveyed the damage. Wounded cadets said that a man in civilian clothes had detonated an explosive device in a crowd of cadets as they were being dismissed for the weekend. Government officials confirmed witnesses’ accounts that the bomber initially survived the attack but soon succumbed to his wounds.

“He was able to sneak in due to the large crowds,” said Ta’il al Riayshi, a police academy employee, holding ball bearings that he said were part of the device the bomber used. “Thank God there weren’t more killed.”

Although the Yemeni military, backed by local fighters and American intelligence and air support, has been able to make gains against the militants, few Yemenis have questioned the continued threat posed by al Qaida in the Arabian Peninsula and its allies. The bulk of the fighters were able to escape the offensive, taking refuge in more secluded hideouts or, in some cases, reintegrating into society.

While the progress in Abyan has been hailed as a significant military victory, many analysts have cautioned that Ansar al Shariah’s withdrawal bears the signs of a tactical retreat. With the militants no longer concentrated in Abyan and apparently shifting to a strategy of more isolated attacks, the analysts said, the shape of the threat posed by al Qaida and its affiliates has changed significantly.

“In the face of the military assault, al Qaida and its supporters realized they couldn’t hold land,” said Faris al Saqqaf, a Yemeni analyst. “They’ve changed their strategy . . . and it’s necessary that the Yemeni government changes its strategy as well.”

Since May’s suicide bombing, Yemeni officials have claimed a number of successes, announcing the arrests of nine terrorist cells and declaring that they’ve thwarted a number of planned attacks. But Wednesday’s bombing – little more than a week after a senior Yemeni intelligence official was assassinated with a car bomb – demonstrated the steep challenges that security forces face as they attempt to restore security to Sanaa, the capital, to say nothing of the rest of the country.

Last month, a suicide bomber also killed Gen. Salem Ali Qatan, the commander of Yemen’s southern military district and a leader of the government’s fight against al Qaida, as he traveled through the southern port of Aden.

Residents of Sanaa have reacted to the attacks largely with disgust. In this economically stagnant nation, the military and police force are seen as among the few reliable sources of jobs. A large proportion of the capital’s residents have at least one relative who works for the police or armed forces.

Many said the perpetrators had succeeded in their assumed goal, robbing the capital’s residents of their sense of security.

“It’s disgusting, to choose targets like this,” said Yahya al Ghaithi, a college student who was discussing the bombing with neighbors in Sanaa’s historic old city. “It’s become hard to feel safe here.”