SAN FRANCISCO - Three Muslim families have filed complaints against an amusement park chain in California that they say barred them from riding go-karts while wearing headscarves, family advocates said Tuesday.The families claim in two locations in the state Boomers! Parks violated their civil rights with an unfair safety policy that bans all headgear on the rides, said Sammar Miqbel, a spokeswoman for the Council on American-Islamic Relations, which filed the complaints on behalf of the families.The United Sikh's organization said it was preparing to file a similar complaint on behalf of a Sikh family.CAIR's Miqbel said the families visiting Boomers! in the San Francisco suburb of Livermore and the Los Angeles suburb of Irvine had been allowed to wait in line for go-karts, but were barred when they reached the front of the line."We share their safety concerns," Miqbel said. "We just ask that Boomers! approach this (in a way) that won't exclude an entire group of people."The parks ban all head-wear on go-karts rides because it could get caught and injure a rider, said Michele Wischmeyer, a spokeswoman for Palace Entertainment Holdings, which owns Boomers! Scarves and baseball caps alike are not allowed, she said."It's not a matter of discrimination, race or religion," Wischmeyer said. "It's a matter of safety."