Bombers killed up to six people on Thursday in the Pakistani city of Peshawar, where a woman suicide attacker blew herself up and roadside explosives struck a police vehicle, officials said.

In the first deadly attacks in the Taliban-hit northwest since the start of the fasting month of Ramadan, a woman threw a hand grenade at a police checkpost, and then blew herself up, senior police official Shafqat Malik told Agence France Presse.

Pakistani troops backed by attack helicopters clashed with Taliban fighters in the main town of the notorious North Waziristan tribal district, witnesses and officials said.

The rare clashes came one day after a bomb killed three Pakistani soldiers and although military officials confirmed troops were in action, there was no sign it was the start of a major offensive, long demanded by the Americans.

Two policemen were killed and five others were wounded Wednesday when dozens of Taliban militants attacked a Pakistan police check post in the northwestern capital Peshawar, police said.

Police said they had initially repelled an attack by a group of armed Taliban on a security check post in Sarband, a suburban area of Peshawar around midnight (19:00 GMT Tuesday).

A car bomb tore through a packed Pakistani market on Wednesday, killing nine people in the sixth attack in the northwestern city of Peshawar in less than a week, officials said.

Police said the bomb was planted in a car and exploded near a police station, destroying shops and vehicles as civilians thronged the congested area at the start of the working day in the Taliban-hit city.