Al-Qaeda's operational chief for Afghanistan and Pakistan has been killed in a US drone strike in Pakistan's lawless tribal border areas, Pakistani security officials said Tuesday.

A covert American drone campaign has this month ramped up attacks on Al-Qaeda and Taliban operatives in the region as part of efforts to bring an end to a nine-year war in Afghanistan so that US troops can return home.

Sheikh Fateh was reportedly made Al-Qaeda chief in Afghanistan and Pakistan after Al-Qaeda's purported number three and former Osama bin Laden treasurer Mustafa Abu al-Yazid was killed on May 21, in another apparent drone strike.

Fateh, whom the intelligence officials said was also killed in North Waziristan, is relatively unknown and his name -- a likely nom de guerre -- does not feature on the US list of most-wanted terrorists.

But security analysts said that any killing of a senior Al-Qaeda operative would be a victory for the US campaign.

Pakistani security officials said the Egyptian was killed on Saturday in a US drone strike on North Waziristan, a hub of Al-Qaeda and Taliban commanders where the covert American missile war has been concentrated.

Reports of high-profile killings by drone strikes -- which the US military as a rule does not confirm -- are generally based on intelligence intercepts, with much of the semi-autonomous region off limits on the ground.

"Yes, he has been killed," one Pakistani security official told AFP on condition of anonymity.

Suspected US aircraft have significantly stepped up attacks on Taliban and Al-Qaeda-linked operatives in the country's semi-autonomous border areas with Afghanistan this month, with at least 21 attacks reported in September.

Two other Pakistani intelligence officials confirmed Sheikh Fateh's death, also speaking on condition of anonymity because they were not authorised to release the information to the media.

"He was head of Al-Qaeda in Afghanistan and Pakistan," one official said. Locally, he was known as Abdul Razzaq, the official added.

"He was in a Datsun pick-up. He was accompanied by three local people. Two of them were identified as Haji Niaz and Naimatullah. They were killed in a drone attack on September 25," the official said.

Shortly after Saturday's attack, Pakistani officials reported four militants killed in a strike on a vehicle in Datta Khel village area near the town of Miranshah, but there had been no immediate word on their identities.

On Tuesday, another US drone killed four more militants, destroying a rebel compound in Zeba village close to the Afghan border in the district of South Waziristan, Pakistani intelligence officials said.

The identities of the dead were not immediately clear.

September has seen the highest number of suspected US drone attacks in a single month, surpassing the previous high of 12 in January, according to an AFP tally.

The Wall Street Journal reported that the CIA had stepped up the attacks to try to foil a suspected terror plot against European targets, which was believed to target multiple countries, including Britain, France and Germany.

Washington has branded Pakistan's northwestern Federally Administered Tribal Areas (FATA), which lies outside government control, a global headquarters of Al-Qaeda and the most dangerous place on Earth.

"It seems the US has reinforced its intelligence gathering and capabilities in FATA and that is why we have seen more than 20 strikes (so far this month)," Pakistani security analyst and author Imtiaz Gul told AFP.

"Al-Qaeda might be running out of senior experienced operational commanders in these strikes," Gul said.

Although the US military does not as a rule confirm drone attacks, its armed forces and the Central Intelligence Agency operating in Afghanistan are the only forces that deploy pilotless drones in the region.

Around 1,140 people have been killed in around 140 drone strikes in Pakistan since August 2008, including a number of senior militants and Pakistani Taliban chief Baitullah Mehsud.