This video from the USA says about itself:
26 December 2015
According to a Bureau of Alcohol, Tobacco, Firearms and Explosives spokeswoman a Friday fire at a Houston mosque had “multiple points of origin” and “appears suspicious.” Center president M.J. Khan said the Islamic Center of Houston caught fire after Friday prayers, when the place was “pretty much empty.”
According to officials and CNN affiliate KTRK, no injuries were reported in the two-alarm fire, drawing 80 firefighters. Special Agent Nicole Strong of the ATF’s Houston Field Division said the agency assisted in the investigation as it typically does “when houses of worship are affected.”
From AFP news agency:
U.S. authorities probe ‘suspicious’ fire at Texas mosque
Saturday, 26 December 2015
U.S. authorities on Saturday were investigating a suspicious fire at a mosque in Texas, weeks after a mass shooting in California by a Muslim couple that sparked fears of a backlash against members of their faith.
No one was hurt in the blaze at the Masjid mosque in Houston that broke out Friday afternoon and destroyed the interior of the small house of worship located in a shopping mall, local media reported.
The fire had “multiple points of origin” and “appears suspicious,” a spokeswoman for the Bureau of Alcohol, Tobacco, Firearms and Explosives told local media.
The Council on American-Islamic Relations urged authorities to probe possible foul play.
“Because of the recent spike in hate incidents targeting mosques nationwide, we urge law enforcement authorities to investigate a possible bias motive for this fire,” the executive director of the group’s Houston chapter, Mustafaa Carroll, said in a statement.
“Officials are checking surveillance video and say the cause of the fire is ‘suspicious,’” the statement said.
The Federal Bureau of Investigation is also looking into the incident, according to local news reports.
Earlier this month, authorities investigated a suspected case of arson at a mosque in Palm Springs, California.
On Dec. 2, a Muslim couple killed 14 people and injured 22 others in an assault in the California city of San Bernardino that is being investigated by the FBI as a terror attack.
The rampage has raised fears of a backlash against the Muslim community in the United States, especially in the wake of anti-Muslim rhetoric by Republican White House hopeful Donald Trump.
A fire at a Houston mosque on Christmas was intentionally set, fire department says: here.