Pakistan accused al Qaeda of killing opposition leader Benazir Bhutto, whose assassination has plunged the nuclear-armed country into crisis and triggered bloody protests. But a spokesman for the al Qaeda leader the government named denied that he was responsible for the killing, while Bhutto's party dismissed the official explanation.
Her Pakistan People's Party (PPP) said President Pervez Musharraf's embattled administration was trying to cover up its failure to protect her.
Officials said at least 31 people had died in violence since a suicide attacker killed the 54-year-old former prime minister on Thursday, stoking fears a January 8 election meant to restore civilian rule to the U.S. ally could be put off.
The violence still had Pakistanis on edge today.
"There's a lot of rioting going on in my neighbourhood, Clifton. Everything has been burned up. Shops have been looted," Ali Khan, 36, country manager for Audi Pakistan, told Reuters as he stood outside his Audi garage in Karachi's business district.
He said he had heard another company's garage was burnt down, "so that's why I'm picking up one of our cars", he said.
Late yesterday, Interior Ministry spokesman Javed Iqbal Cheema told a news conference: "We have intelligence intercepts indicating that al Qaeda leader Baitullah Mehsud is behind (Bhutto's) assassination."
Mehsud is one of Pakistan's most wanted militant leaders and is based in the South Waziristan region on the Afghan border. Cheema said authorities recorded an intercept yesterday in which Mehsud had congratulated his people for the attack.
However, a spokesman for Mehsud denied the claim. "I strongly deny it. Tribal people have their own customs. We don't strike women," Maulvi Omar said by telephone from an undisclosed location.
Bhutto's Pakistan People's Party also rejected the government's version. A spokesman said the government must show solid evidence. "The government is nervous," he said. "They are trying to cover up their failure" to provide adequate security.
Tens of thousands of Bhutto's supporters wept and beat their heads as she was laid to rest yesterday. Troops were called out to quell protests in her home province of Sindh, where she had huge support, particularly among the rural poor.
Many mourners chanted slogans against Musharraf and the United States, which backs the former general in the hope he can ensure stability in the face of Islamist violence and relies on Pakistan as an ally against al Qaeda and Afghanistan's Taliban.
Musharraf, who seized power in a military coup in 1999 but left the army last month to become a civilian president, has appealed for calm and blamed Islamist militants for the killing. But many accused him of failing to protect Bhutto, who died in the garrison city of Rawalpindi, home of the Pakistani army.