Transcript: the Taleban in Afghanistan have told the BBC that the group is changing its tactics by targeting the capital Kabul. Taleban spokesman Zabiyullah Mujahed was speaking to BBC world affairs editor John Simpson:

JS: The Taleban led us to expect that there would be a big spring offensive, yet none has materialised.

ZM: I absolutely reject the suggestion that we have been defeated. Our operation continues, and gathers momentum day by day.

We know our power, and compared with last year, we have quadrupled our operations all over Afghanistan.

As for the spring offensive, our leadership had some problems and there was a lull, but then we were able to recover.

JS: What problems?

ZM: Some members of our leadership were killed.

JS: Nato forces say they have infiltrated the Taleban. Is this true?

ZM: The enemy has tried to infiltrate the Taleban ranks, and has targeted our leadership. Thank God, they haven’t been too successful.

We are trying to catch their spies. Unfortunately, some have succeeded. But now we are using counter-intelligence to find these people.

JS: Does last Sunday’s bomb in Kabul mean that you are shifting your campaign to Kabul?

ZM: With each passing day, taking into account the enemy’s tactics, we are changing our own tactics. It is true we are increasing our pressure on Kabul, because Kabul is the capital city and the foreign troops are concentrated there. This is our next main target. God willing, we will be successful.

JS: How important to you is the struggle in Iraq?

ZM: Our enemy is the same, and we are repeating the tactics which they use in Iraq. They have proved effective in defeating the enemy. Our goal is the same – the independence and freedom of our country.

JS: Are you experiencing any problems in getting people to be suicide bombers?

ZM: We have a lot of people who are ready to carry out attacks. The numbers are growing. A lot of people are coming to our suicide bombing centre to volunteer. We have a problem with making sure they attack the right targets, avoiding killing civilians. It takes time to train them properly.

JS: Every suicide bombing kills innocent people. Don’t you have a problem getting people to carry out the kind of mass murder we saw here last Sunday?

ZM: Using explosives in war always involves casualties. We do our best in our suicide attacks to avoid civilian casualties. These are our Muslim countrymen, and we are sacrificing our blood to gain their freedom. Their lives are important to us, of course.

But fighting with explosives is out of the control of human beings. As a result, there are casualties. But our opponents also kill ordinary people.

JS: Do you care about the lives of the people you kill?

ZM: Of course it’s regrettable for us. But I can tell you, that no fighting is possible anywhere in the world without this. During the Soviet invasion we lost a million and a half people, all of them innocent.

But the important thing for us was to gain our freedom and independence.

JS: People in Nato say they will have a big presence here for 30 years.

ZM: When they came to Afghanistan, they had big objectives. They wanted to occupy the country and root out the Taleban and extend their control throughout our country in a short period of time.

But we are certain we will win, because for us independence is important. For the Nato forces, the lives of their soldiers are important.

There will be a big fuss in the Western parliaments, asking that their sons should not be killed in Afghanistan. This means we will defeat them.