Islamabad - At least 20 people, including five policemen and eight Taliban militants, were killed Friday in a suicide bombing and army airstrikes in Pakistan's tribal region and the neighboring North-West Frontier Province (NWFP), officials and media reports said.

A suicide bomber blew himself up outside the office of a senior police officer, killing five policemen and four civilians in NWFP.

Deputy Inspector General of Police Akhtar Ali Shah said the attack against a vehicle of his security escort took place when he was about to leave his office in Mardan, some 50 kilometres north-east of provincial capital Peshawar.

"I was the target of the attack," he told English-language Dawn news channel.

"From evidence collected from the site it appears to be a suicide attack. The skull and limb of the suspected suicide bomber have been found," Shah said. He was not hurt in the attack.

His deputy Iqbal Khan said the bomber, who was on foot, detonated the explosives when he was "challenged by an officer on duty."

"Four policemen and four civilians died on the spot while another police officer succumbed to injuries at the hospital," he added.

Twelve people were injured in the incident.

No one has claimed the responsibility but the NWFP and rest of the country has seen intensified attacks by Taliban militants targeting security officials and political leaders.

The bombing campaign has created an atmosphere of fear and uncertainty, driving away foreign investors, and leaving the country's economy crippled.

Pakistan's foreign reserves have dropped some 75 per cent over the last 12 months, from 18 billion dollars to around 4.3 billion. At the same time, the rupee has weakened by more than 27 per cent against the dollar.

This has forced the nuclear-armed Islamic country to seek an IMF bailout program to avert default on its external payments. The first round of talks between the sides concluded on Thursday in Dubai.

Separately, eight Taliban militants were killed when army helicopter gunships pounded their positions in Mamoond area of Bajaur tribal district, where security forces are engaged in operations against insurgents launching cross-border attacks on US-led forces in Afghanistan, the Urdu-language Aaj news channel said.

One of the shells hit a residential area, destroying a mud house and killing two children and a woman, it reported further.

According to official data, the security forces killed more than 1,500 militants and arrested some 950 since early August.

Major General Tariq Khan, inspector general of the paramilitary Frontier Corps, told reporters last week that the government forces have so far lost 73 soldiers - 42 army and 31 paramilitary soldiers - while 269 were injured in the fighting. (dpa)