A wave of attacks against top security installations over the last several days demonstrated that the Taliban, al-Qaeda and militant groups once nurtured by the government are tightening an alliance aimed at bringing down the Pakistani state, government officials and analysts said.

The assaults in Lahore on Thursday, coming after a 20-hour siege at the army headquarters in Rawalpindi last weekend, showed the deepening reach of the militant network, as well as its rising sophistication and inside knowledge of the security forces, officials and analysts said.

The umbrella group for the Pakistani Taliban, Tehrik-e-Taliban, claimed responsibility for the attacks in Lahore, the Geo News reported on its website.

But the style of the attacks also revealed the closer ties between the Taliban and al-Qaeda and what are known as jihadi groups, which operate out of southern Punjab, the country’s largest province, analysts said. The cooperation has made the militant threat to Pakistan more potent and insidious than ever, they said.

The government has tolerated the Punjabi groups, including Jaish-e-Muhammad and Lashkar-e-Jhangvi, for years, and many Pakistanis consider them allies in just causes, including fighting India, the United States and Shiite Muslims. But they have become entwined with the Taliban and al-Qaeda, and have increasingly turned on the state.

The alliance has now stepped up attacks as the military prepares an assault on the Taliban stronghold of South Waziristan.

“These are all Punjabi groups with a link to South Waziristan,” Aftab Ahmed Sherpao, a former Interior Minister, said, explaining the recent attacks.