Tunisian authorities say third bomb scare was a hoax TUNIS (Reuters) - Tunisia's interior ministry said on Saturday that a suspected bomb placed near a colonel's home in Tunis was fake and came with a letter, purporting to be from al Qaeda, demanding the army stop its offensive near the Algerian border. Tunisian security forces launched major ground and air attacks on Friday in Mount Chaambi to try to rout Islamist militants, who launched a deadly assault on the army this week. The box contained only wires and batteries, the ministry said in a statement. "It was not a real explosive but rather a fake bomb," it said. The letter found had threats from al Qaeda demanding that the operations in Chaambi stop. The hoax happened just hours after two men, suspected of being radical Islamists, accidentally set off explosives at home. One of them was killed by the bomb he was making and, in a separate incident, the other blew off his hand and was captured. Islamist militants have stepped up attacks on Tunisian security forces this week, adding to instability over a growing political crisis. The secular opposition is trying to oust a transitional government led by moderate Islamists, who deny any links to the radical groups attacking security forces. On Monday, Islamist militants ambushed and killed eight soldiers in the sparsely populated Chaambi area, where the army has been hunting Islamist militants since December, in one of the worst attacks on security forces in decades. The assault followed two bomb attacks near security forces in the capital, the first time Tunis has suffered such attacks. While security forces fight militants, the government will be meeting with opposition groups on Saturday to try to solve the country's political turmoil. Both sides have appeared to be escalating tensions in a week of rival protests. The ruling Ennahda party is organizing a protest on Saturday in support of the government. On Sunday, opposition groups are planning an anti-government march. Reporting by Tarek Amara; Writing by Erika Solomon; Editing by Louise Ireland