SANA, Yemen — Yemeni security forces killed a suspected al Qaeda cell leader and captured four other militants Wednesday morning, hours after two soldiers were killed by Qaeda members in a neighboring district, Yemeni officials said. The clashes were the latest episode in the Yemeni government’s heightened campaign against al Qaeda’s Arabian branch, a terrorist organization once based in Saudi Arabia and run by a Saudi, and now based in Yemen and run by a Yemeni. Raids have grown more frequent and have drawn on increased help from the United States, which declared the regional al Qaeda affiliate a global threat after it claimed credit for the failed effort on Christmas Day to blow up an airliner approaching Detroit. Yemen’s Interior Ministry identified the dead militant as Abdullah al Mehdar, one of the country’s most wanted militants. He was killed after Yemeni commandos broke into the barricaded house where he was holed up with fellow militants in the city of Houtah, according to a statement posted on the Interior Ministry’s Web site. Houtah is in Shabwa Province, one of several remote areas where al Qaeda militants have taken refuge in recent years. Earlier, Saudi Arabia’s assistant defense minister, Prince Khaled bin Sultan, said Tuesday that Saudi forces had killed hundreds of Yemeni rebels who had occupied a border village, as fighting between the rebels and Yemen’s military also intensified nearby in the Yemen city of Sadah. The developments signaled a concerted push by the Saudi and Yemeni governments to try to end an ongoing conflict that has flared into all-out war since the summer. The conflict between Yemen and the Houthi rebels, named after the clan of their leader, also spilled over the border into Saudi Arabia, prompting Saudi forces to begin their own offensive on Nov. 4 to push the rebels back. In announcing that Saudi forces had managed to “cleanse” the border village, Al Jabri, of the Yemeni rebels who had occupied it, Prince Khaled said that 82 Saudi soldiers had been killed since the kingdom moved against the rebels who it says crossed into their territory, The Associated Press reported. At the same time, Yemeni officials reported attacking Houthis in the city of Sadah, the capital of Sadah Province, where fighting has been centered for months. The Yemenis said they had killed 20 rebels and arrested 25. The Houthis, in an Internet posting, said the military had used bulldozers to level houses and force the rebels into the open, according news agency reports. On Monday, Yemen’s deputy interior minister, Muhammad al Qawthi, said the Yemeni military was starting a focused operation intended to finish off the Houthi rebels, though that prospect seemed unlikely anytime soon. The conflict, which has simmered for years, has intensified since August. The Houthis, a Shiite rebel group, gained control of sections of Sadah Province, a remote, mountainous area in the north. That fighting, however, is only one of the many problems the central government faces as it tries to maintain — or reassert — control over a nation fractured by geography, ideology, allegiance and tribal affiliation. Yemen, a poor, dry country in the southern corner of the Arabian Peninsula, has also emerged as the center of Al Qaeda’s regional affiliate. The United States has said it plans to increase aid to Yemen to help its counterterrorism operations. Yemen has said it will not allow foreign troops to operate on its territory. “The issues such as Al Houthi terrorist gang in Sadah Province and acts of chaos by elements belonging to Al Qaeda movements in the southern provinces are all issues that come within the internal Yemeni matter,” said the foreign minister, Abu Bakr al-Qirbi, according to a Yemeni government Web site. Robert F. Worth reported from Sana, Yemen, and Michael Slackman from Cairo..