Two bombs exploded in a crowded market in a Christian-dominated town in central Indonesia on Saturday, killing at least 22 people and wounding 40, police said. The blasts came two days after unspecified security threats prompted the United States to close its diplomatic offices.

The explosions within 15 minutes of each other flattened food stands in the Sulawesi (search) island town of Tentena (search). Witnesses said many of the victims had come to help those injured in the first blast, only to be killed by a second, larger explosion that left a 3-foot-deep crater. The blasts also damaged a bank, a church and a police station.

No one claimed responsibility for the bombings at the meat and produce market, but Vice President Jusuf Kalla (search) said they were not connected with ongoing sectarian violence between Muslims and Christians.

"It was carried out by the terrorists instead of warring Muslim and Christian factions," Kalla said, without offering proof. "The motive of the perpetrators is to disturb the security situation in Poso."

On Sunday, police guarded the bomb site, where bodies still lay strewn among fruits and vegetables.

"The bodies are everywhere. Some have lost their legs or their arms," said Eman Longkar, who witnessed the blasts.

A Christian clergyman and a 3-year-old boy were among the dead, police said.

More than 90 percent of Indonesia's 210 million people are Muslims. It is the world's most populous Muslim nation, but central Sulawesi has roughly equal Muslim and Christian populations.

Tentena, site of the market bombings, is 35 miles from Poso, where fighting between Muslims and Christians claimed at least 1,000 lives in 2000-2002.

Rinaldy Damanik, a Christian clergyman and leader of the Synod Churches of Central Sulawesi, also ruled out the involvement of local groups.

"The blasts were different with what happened here in the past," he said. "This has nothing to do with the sectarian conflict. This is the work of uncivilized terrorists who just don't want to see peace in this region."

Others were careful not to fan already deep tensions.

"The Christian people here do not want revenge," said police Sgt. Sumondak. "We do not yet know who did this."

Police later discovered an unexploded bomb outside a nearby church, said Poso district chief Andi Asikin Suyuti.

In January, police found 60 homemade bombs in an abandoned house in Poso, and security officials last year blamed the Al Qaeda-linked Jemaah Islamiyah group for attacks that killed at least 12 Christians.

On Thursday, the United States closed its embassy and diplomatic offices — including those in Jakarta, Surabaya, Medan and the island of Bali — until further notice, citing security concerns.

Police said they did not know of any specific threats against Americans but added that they had intelligence indicating that Malaysian terror suspects Azahari bin Husin and Noordin Mohamed Top might be planning attacks.

National police spokesman Maj. Gen. Anang Budihardjo said he could not rule out the possibility that Azahari played a role in the latest Poso bombing.

"I cannot say (the bombs) were the work of Azahari's group, but because he has been a fugitive for long, it is possible that he has recruited new members in the region," the spokesman said Saturday.

The two Malaysians are believed to have masterminded two of the worst past attacks: a Sept. 9, 2004, blast at the Australian Embassy in Jakarta that killed 10 people, and an Aug. 5, 2003, blast in Jakarta that killed 12 at a Marriott hotel.