The US Central Intelligence Agency (CIA) has carried out 20 drone strikes so far in September on suspected Taliban strongholds in the mountains of Pakistan, The New York Times reported Tuesday.
The number is the highest of any month, the Times said. In January, the CIA carried out 11 strikes, the next highest monthly total, DPA reported.
The escalating strikes are part of the US effort to undermine the Taliban, which uses Pakistan as a base from which to attack NATO troops in Afghanistan.
US President Barack Obama has beefed up the drone operations in Pakistan amid growing frustration that Pakistan's government has not done enough to oust militants from its western mountains.
The Times also quoted unnamed military officials as saying that US military helicopters launched three rare airstrikes into Pakistan in recent days that killed 50 suspected members of the Haqqani network, a militant group led by Afghan warlord Jalaluddin Haqqani and his son, Sirajuddin Haqqani.
The group has been blamed for launching cross-border raids on NATO-led international forces in Afghanistan.