SOCHI, Russia (AP) – About 100,000 police, security agents and army troops have pledged to make the 2014 Winter Olympics in Sochi, “the safest Olympics in history”. But the world wide concerns of a possible suicide bombing has yet to subdue.

Security experts are not confident in the game protection against the threats from Islamic militants in the Caucasus. The areas raising the most concern are soft targets away from the Olympic sites or even outside Sochi. The possibility of jihadists already inside Sochi security was made apparent by the experts.

“The most daunting threat is suicide bombers,” Grigory Shvedov, chief editor of the Caucasian Knot, an online news portal focusing on the Caucasus, told The Associated Press.

He said 124 suicide attackers have struck Russia over the past 13 years.

Police in Sochi have begun blanket police checks of city residents and issued leaflets with warning about three potential suicide bombers. One threat is a 22-year-old widow of an Islamic militant, and said to be at large in the city. Authorities also expelled thousands of migrant workers in attempt to better police possible threats.

Sochi has taken nearly all possible preparations  against terrorist attacks with air defense missiles, drones, high-speed patrol boats and sophisticated sonars capable of spotting submarines.

Protest over Russian anti-gay law

On Friday,  an open letter to the 10 biggest Olympic sponsors, urging them to denounce the law and run ads promoting equality for lesbians, gays, bisexuals and transgender people. The writers of the letter were 40 human-rights and gay-rights groups from the U.S., Western Europe and Russia – including Amnesty International, Human Rights Watch and the Human Rights Campaign.

“LGBT people must not be targeted with violence or deprived of their ability to advocate for their own equality,” the letter said. “As all eyes turn toward Sochi, we ask you to stand with us.”

The International Olympic Committee and top sponsors have expressed general opposition to discrimination and pledged to ensure that athletes, spectators and others gathering for the Games would not be affected by the law. The IOC has also encouraged athletes to not make  political gestures while on medal podiums or in other official venues, but says they are free to make political statements at news conferences. Putin has given similar assurances in regard to Sochi, but remains committed to the law’s broader purposes.

Australian snowboarder Belle Brockhoff told Australia’s Courier-Mail newspaper that she plans to participate in than the competitions she qualified for.

“After I compete, I’m willing to rip on his ass,” she told the newspaper. “I’m not happy and there’s a bunch of other Olympians who are not happy either.”

Brockhoff is one of several Olympians promising to display the logo P6 – a reference to Principle Six of the Olympic Charter that says any form of discrimination “is incompatible with belonging to the Olympic Movement.”

The movement will be promoted via social media by organizer of the P6 campaign, Hudson Taylor, who hopes other athletes will contribute a fair share.