Wichita ? Investigators are trying to determine if anti-Islam letters sent to a mosque in west Wichita are connected to a fire that caused serious damage to the building on Monday.

The leader of the Islamic Association of Mid Kansas, Abdelkarim Jibril, said the mosque received about eight letters starting four to six months ago, although the letters stopped about a month ago, The Wichita Eagle reported. The letters criticized Islam, called the prophet Muhammad a pig and contained drawings that mocked the prophet.

The leaders of the mosque had planned to turn the letters over to authorities but had not done so before a fire struck the mosque Monday morning, Jibril said.

“We don’t know if any of the letters have any relationship to the fire at this point. It’s something we’re looking into though,” said Wichita fire Lt. Troy Thissen.

The FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives joined the fire investigation Monday.

The blaze, which was reported at 12:45 a.m. Monday, spread quickly. It caused at least $130,000 damage but might have totaled the mosque because of extensive damage to the attic and roof supports, Wichita fire Capt. Stuart Bevis said. The cause of the fire has not been determined.

“We’re going to be taking a lot of steps” to review evidence because the fire involves a religious meeting place, Bevis said.

Jibril, who has been president of the association for most of its 32-year history, said it appeared the letters were written by the same person because they contained the same types of pictures and same handwriting.

One of the messages said “I don’t need to know anything else about you but 9/11,” and another contained drawings of Muhammed with a beard, Jibril said.

“We don’t allow pictures of the prophet,” he said. Most of the letters were mailed from somewhere in Texas, he said.

About 30 or 40 people attended Friday services at the mosque, which also held Sunday school classes, classes in Arabic, holiday prayers and other gatherings, said Jibril, who said it would be rebuilt.

Hussam Madi, a spokesman for the Islamic Society of Wichita, who delivered sermons at the mosque, said the fire was “very, very sad” for the people who prayed there.

Although two mosques are available in east Wichita, the mosque on the west side served members of the Muslim community throughout the city, Madi said. Muslims who fly out of town on Fridays often stop there to pray before they leave, he said.