One of southeast Asia's most-wanted terrorist suspects, accused of plotting a series of deadly bombings in Bali, was believed to have been killed Wednesday when an elite Indonesian anti-terrorism unit stormed a suspected militant hideout, police said.

Azahari bin Husin, a Malaysian accused of leading an Al Qaeda-linked group and masterminding at least four deadly blasts in Indonesia in recent years, either was shot to death or blew himself up to avoid capture, senior police official Gen. Gorries Mere told The Associated Press.

Local TV stations reported that Azahari, who security officials have said always wore explosives around his waist to avoid being captured alive, blew himself up during the operation.

"The suspicion is that (Azahari is dead) but we will confirm it tomorrow," national police chief Gen. Sutanto told reporters at the scene, adding that investigators were not immediately entering the villa because of fears it was booby-trapped.

Those inside the house detonated at least 11 explosions and fired at police. Two others inside the villa also were killed, police said. Forensic experts will run DNA tests on the remains, Sutanto said.

"The last one, the big one, was a suicide blast, that is the one that killed them," he said.

The U.S.-trained anti-terrorism unit raided the suspected terrorist hide-out in Malang, a town about 528 miles east of Jakarta on Java island, at about 4 p.m. Wednesday, Mere said.

Witnesses told the SCTV network they heard two explosions and gunfire before police moved in on the house. The building's roof was blown off, Jakarta's Metro TV news station.

Local military commander Maj. Gen. Syamsul Mapparepa said those inside the house "were putting up stiff resistance, and were throwing grenades," the state news agency Antara reported.

Officials say Azahari, who is in his 40s, is a key member of the Al Qaeda-linked terror group Jemaah Islamiyah. The group wants to establish an Islamic state spanning Indonesia, Malaysia, Singapore and the southern Philippines.

Azahari and fellow Malaysian Noordin Mohamed Top are accused of direct involvement in four deadly terrorist attacks in Indonesia, including the 2002 Bali bombings that killed 202 people.

Indonesian officials named the two Malaysians as the suspected masterminds of last month's triple suicide attack on the same resort island that killed 20 people.

Maj. Gen. Ansyaad Mbai, a top Indonesian anti-terror official, confirmed that a major operation was under way in Malang targeting Azahari and his group. He said he did not know whether Azahari was killed. One policeman was shot and injured, he said.

Officials say Azahari joined Jemaah Islamiyah in the late 1990s and trained in an Al Qaeda camp in Kandahar, Afghanistan.

Jemaah Islamiyah has been weakened by a crackdown since the Sept. 11 terrorist attacks in the United States.

But analysts say Azahari, an explosives expert who studied engineering in Australia and earned a doctoral degree in Britain, is a key leader in rebuilding the group. He has moved between Malaysia, Thailand and Indonesia in recent years.

Ken Conboy, a Jakarta analyst who wrote a recent book on Jemaah Islamiyah, said Azahari was among the top five leaders of the Southeast Asian terror group.