Drone attacks are widely unpopular in Pakistan due to the civilian casualties they have caused [EPA]

Two suspected US drone raids have killed seven fighters in northern Pakistan, officials say.

Four of them were killed by missiles fired on a compound near the city of Miran Shah in North Waziristan early on Thursday, according to intelligence sources.

The area is considered a stronghold of the al-Qaeda-linked Haqqani network.

An intelligence official identified one of the dead as "Jalil", a cousin of the network's leader Sirajuddin Haqqani.

"Jalil was a highly trusted companion of Sirajuddin. He had been with the Haqqani group for a long time and was tasked with handling communications," the official said.

Later in the day, three missiles were fired at a group of fighters in the Bermel Tehsil area of South Waziristan.

Three people were said to have been killed in the raid.

The US does not confirm its drone strikes in Pakistan, but its forces are the only ones that deploy the unmanned Predator aircraft in the region.

US-Pakistani ties strained

About 30 drone raids have been reported in Pakistan since elite US forces killed al-Qaeda chief Osama bin Laden near Pakistan's main military academy in Abbottabad, close to the capital, in May.

The operations have angered many Pakistanis as hundreds of civilians have been killed since the raids began in 2008.

The Pakistani government publicly protests the operations, but is believed to support them.

The latest raids came as US special envoy to Afghanistan and Pakistan Marc Grossman arrived in Pakistan to improve ties between Washington and Islamabad.

Last month, senior American officials accused Pakistan's spy agency of assisting the Haqqani network in attacks on Western targets in Afghanistan, including a strike on the US embassy in Kabul.

They were the most serious allegations yet of Pakistani duplicity in the 10-year war in Afghanistan and sent already strained ties between Islamabad and Washington plunging further.

US officials have since backtracked somewhat on the claims, but the Haqqani network remains a key issue in ties between the countries.