At least 15 people were killed and over 80 injured when suspected Palestinian suicide bombers carried out simultaneous explosions on two buses in the southern Israeli city of Beersheva on Tuesday afternoon.

It was the first terror strike in the city, 15 km from West Bank.

The attack came hours after Prime Minister Ariel Sharon presented the Knesset faction of his Likud party with a timetable for the approval of his disengagement plan calling for withdrawal from Gaza, and warned party rebels that the plan "will be implemented, period".

The buses were full of parents and children shopping for educational items on the final day of the school holidays in the country, witnesses said.

Minister for Internal Security Tzachi Hanegbi said, "Where there is a fence there is no terror and where there is no fence there is terror. This is what we have learnt from the last six months."

The minister said he would ask the government to construct a fence in areas bordering Beersheva also.

"We don't know yet the identity of terrorists," police chief Moshe Karadi said.

He also called for construction of a fence in the area and said more police would be deployed when schools open on Wednesday.

A witness, Doron, said, "There was a foul smell of burnt human flesh soon after the blasts. The incident now exposes the whole of Israel to such attacks as this southern city was considered safe in view of the large presence of the minority community around."

"A silence prevailed before screams could be heard and the rescue workers reached the place with sirens of ambulances," said another witness Miriam, working for the Beersheva municipality close to the site of the blasts.