A grenade exploded outside a Bangkok hotel and shopping mall, shattering windows and wounding a security guard, police said on Friday. Friday night blast was the second attack in a month near the King Power shopping compound and the latest in a string of low-level explosions that have rattled the Thai capital since May when the army violently suppressed two months of anti-government protests. The protests left 91 dead and 1,400 hurt. No one claimed responsibility for the blast, which occurred about 11 pm on Thursday, said Metropolitan Police commander Maj. Gen. Wichai Sangpraprai. The shopping compound also includes the Pullman Hotel, a business hotel with a popular wine bar in downtown Bangkok. The hotel was spared damage but a half-dozen windows were shattered at the King Power duty-free shopping mall, which was closest to the explosion, Wichai said. A woman who identified herself as the hotel's PR manager but declined to give her name said security had been increased around the hotel but no guests had been affected by the blast. The Thai government has cited the recent explosions as justification for keeping the capital under a state of emergency, which was imposed during the protests. An initial investigation showed that the grenade was similar to the M67 grenade used in previous blasts, said Wichai. He said police were studying CCTV footage for leads. "I think the intention was to threaten and not to take lives," Wichai said. On July 30, a grenade hidden in a garbage bag across the street from the King Power compound exploded and left one passer-by seriously wounded. An earlier July blast at a Bangkok bus stop killed one person and wounded 10. No one has claimed responsibility for any of the blasts, and authorities have declined to link them to the political turbulence.