Increased US drone strikes in Pakistan's tribal areas are linked to a terror plot targeting Europe, Pakistan's US envoy said Wednesday, amid mounting fears that Al-Qaeda is planning a wave of attacks.

Ambassador Hussein Haqqani told the BBC that the increase in strikes in North Waziristan, a reputed militant hotbed, came after intelligence agencies uncovered a plot to "attack multiple targets in Europe."

He also said that a strike on Monday in the district which killed eight militants, including five Germans, was linked to the plot.

"I think that the activity we see in North Waziristan in terms of strikes... is connected to the terrorist warnings that we have heard about potential strikes in Europe," he told the British broadcaster.

But he urged people to stay calm and vowed intelligence agencies would foil any plot.

US drone strikes in Pakistan have increased in recent weeks, with authorities there reporting 24 attacks since September 3 which have killed more than 140 people.

An Al-Qaeda plot planned in Pakistan is targeting Britain, France and Germany but planning for the attacks was at an early stage when intelligence agencies learned of them, according to reports.

Japan, Sweden, the United States and Britain have warned their citizens travelling in Europe of the possibility of a terrorist attack.

US channel Fox News, citing unnamed intelligence officials, said militants had a list of targets in France and Germany, including Paris's Eiffel Tower and Notre Dame Cathedral, Berlin's Brandenburg Gate, the city's central railway station and the Alexanderplatz TV tower.

Haqqani said that "certain people have been arrested in the past, interrogation and other intelligence has revealed that there has been a plot to attack multiple targets in Europe."

"We do not want anybody to panic, there shouldn't be any panic because European, Pakistani and American intelligence services are working together to foil these plots," he added.

The envoy also said Pakistan was committed to fighting terrorists.

"Pakistan has been concerned about the presence of terrorists inside Pakistan or in the regions close to Pakistan for a long time and we have been working very hard at eliminating them."

The strike on Monday that killed the Germans took place in Mir Ali Bazaar, 20 kilometres (12 miles) east of Miranshah, the main town of North Waziristan.

North Waziristan has a reputation as a hideout for foreign and homegrown militants linked to the Taliban and Al-Qaeda, and is the operational epicentre of the latest plot.

Officials in Washington say in the past the strikes have killed a number of high-value targets including former Pakistani Taliban chief Baitullah Mehsud. However, the attacks fuel anti-American sentiment in the conservative Muslim country.

The United States does not as a rule confirm drone attacks, but its military and the Central Intelligence Agency operating in Afghanistan are the only forces that deploy the pilotless aircraft in the region.