An explosion ripped through a residential building in the capital San'a Friday, killing two bombmakers, police said.

The Ministry of Interior said in a statement the homemade bomb went off prematurely, killing one person instantly and seriously wounding another, who later died on the way to a hospital.

One of the victims was identified by police as Mohammed Abdel Khaleq al-Boreihi. The identity of the other and the motive for the bombing were not immediately clear. Police said three people, including one who shared the rented apartment with the victims, were arrested and were being interrogated.

A search of the blown-up apartment revealed explosive materials and weapons, including rocket-propelled grenades, police said.

The early morning blast comes as Yemen cracks down on militants inside its own borders. In recent months, supporters of Usama bin Laden's Al Qaeda terror group have claimed responsibility for a wave of bombings targeting security officials and government offices.

The attacks were said to have been triggered by Yemen's support for the United States and the arrest by Yemeni authorities of suspected Al Qaeda members or sympathizers.

Security in Yemen became a top U.S. concern following the October 2000 attack on the USS Cole that killed 17 American sailors in the southern port of Aden. The attack was blamed on Al Qaeda. Bin Laden, a Saudi dissident, has Yemeni roots.

Yemen has allowed American forces into the country to train its military to combat terrorists. A U.S. team has also began installing a surveillance system at Yemen's sea and air ports to help it keep terrorists from entering or leaving.