TASHKENT, Uzbekistan - This week's outbreak of violence in Uzbekistan is linked to al-Qaida, a top anti-terror official said today - the first time the Uzbek government has directly tied the attacks to the terror network headed by Osama bin Laden.

Ilya Pyagay, Interior Ministry deputy anti-terrorism chief, said operations were continuing to capture suspected terrorists. At least 43 people - mostly alleged terrorists - have died this week in a series of suicide bombings and police shootouts.

"These are Wahhabis who belong to one of the branches of the international al-Qaida terror group," Pyagay said, referring to the strict strain of Islam in which bin Laden was raised. "These are bandits who planned these attacks long in advance."

Prosecutor-General spokeswoman Svetlana Artikova said today the events were "all part of one chain."

The violence that began Sunday is the first unrest to hit this Central Asian nation since it became the United States' key ally in the region after the Sept. 11, 2001, terror attacks, hosting hundreds of U.S. troops at a military base near the Afghan border.

Pyagay said officials were trying to determine the nationality of the 20 alleged terrorists they said died Tuesday. He said many had been carrying false passports in a clash that officers at the scene and witnesses said was sparked after two suicide bombings that killed three police - contradicting official accounts that all 20 blew themselves up.

Uzbek President Islam Karimov initially hinted the attacks were connected to the extremist Islamic group Hizb ut-Tahrir, which has been firmly suppressed in the country. But the group denied involvement and it has no known links to terrorist violence.

The events also appeared to spark the start of a deeper crackdown on independent Muslims.

Human Rights Watch confirmed six arrests in Tashkent and the surrounding region, and another two women and three children were detained overnight and later released, said Allison Gill, the group's Uzbekistan researcher. She said none of them appeared to have a connection to the violence.

"The volume of arrests just in the last 24 hours is high," she said. "It seems (authorities) are using this as a pretext to get people that they wanted anyway."

All land border crossings have been closed until further notice, the Border Protection Committee said. Tashkent's international airport continued to operate. Theaters canceled all performances until Monday, said a ticket agent at Tashkent's main Navoi Theater.