The carpets, each made in the early 1900s specifically for the centuries-old Khawaja Abu Nasr Parsa mosque in northern Balkh province, were spirited away late Monday, said local police chief Mir Hamza. Each of the carpets was about 10 meters (30 feet) long and richly woven in a deep red.

"It is the first time anything has ever been stolen from the mosque," said Hamza. "The first time we have seen looting in God's house. This is a very sad time for the people of Balkh."

The mosque is believed to be one of the oldest in Afghanistan, though its exact age is not entirely clear. It is a popular attraction for Afghan travelers and even some foreigners.

Hamza said authorities believe more than one person was involved in the heist, since the carpets were too big and heavy to be carried by a single man.

There was no sign of a forced entry, so the criminals must have had a key or picked the lock, the police chief said.

Hamza said the only people with keys to the mosque are the chief cleric, his assistant and a security guard, but none of them were at the building when the theft allegedly occurred.

When the cleric's assistant arrived early Tuesday morning to prepare the mosque for prayers, he noticed a switch had been made. The carpets, which Hamza said were priceless, had been replaced by newer and poorly made Iranian carpets worth only about $300 each.

Hamza said he had informed all the carpet and antique shops in the province that they should inform authorities should anybody try to sell the stolen goods. He also warned a government checkpost along the Uzbekistan border, which is about 40 kilometers (25 miles) away, to be on the lookout.

"I told everybody that this is God's property and it must be returned," Hamza said.

Looting of Afghan antiquities is considered a growing problem, and many items are believed to have been spirited abroad.