ISLAMABAD – Pakistan’s army Friday disputed reports that its security forces had tipped off insurgents at bomb-making factories after getting intelligence about the sites from the United States.

The Foreign Ministry also lodged a protest with the American embassy over a purported attack on a Pakistani military post — the latest signs of strained relations since the U.S. killed Osama bin Laden last month without notifying officials here ahead of time.

The army called the assertions of collusion with militants “totally false and malicious.”

American officials told The Associated Press in early June that they’d shared satellite information with Pakistan about two militant bomb-making factories. Within 24 hours, they said they watched the militants clear out the sites, raising suspicions that the Pakistanis had shared the information.

In a statement Friday, Pakistani officials say attempts to destroy four militant bomb-making factories only partly succeeded because intelligence on two of the sites was wrong.

Various media accounts said the factories were in the Waziristan stretch of Pakistan’s tribal belt, where al-Qaida and Taliban fighters have proliferated. The intelligence sharing was part of a U.S. effort to improve the relationship with Pakistan.

Also Friday in Pakistan’s northwest, security forces backed by artillery killed 12 Islamist militants in a tribal region where insurgents have been mounting cross-border attacks from Afghanistan, a government administrator said. Pakistan says the attacks are happening because U.S. and NATO forces are not doing enough to protect the territory on the Afghan side.