Two security guards and an insurgent were killed in an attack in the Afghan capital Kabul, officials say.

Reports said the blast occurred just inside a shopping complex in the city centre after an attacker carrying explosives was challenged by guards.

A gun battle which broke out following the explosion has now ended.

It is the second attack in less than three weeks in the heavily fortified Afghan capital, after nine died in an attack on a supermarket on 28 January.

The Taliban told the BBC they had carried out that attack.

Monday's attack is thought to have begun when an attacker was challenged by security guards as he attempted to gain access to the shopping precinct, says the BBC's Quentin Sommerville in Kabul.

The guards fired on the assailant, and the explosives he was carrying were detonated.

"It was a single blast," interior ministry spokesman Zemarai Bashary told AFP news agency.

"A suicide bomber tried to enter the mall. He was stopped by the guards at the entrance, he blew himself up and killed the two armed private guards and injured two other people nearby," he said. Immediately after the blast there was an exchange of gunfire between insurgents and security forces that continued for up to 20 minutes, our correspondent says, but that has now ended and police have cordoned off the area.

A gun battle broke out in the centre of Kabul after the blasts

Until the attack on the supermarket at the end of January, our correspondent says, things had been less violent in Kabul - which some observers put down to an informal ceasefire operating between the main insurgent network and security forces.

All of this is happening as the Afghan government -- with Nato sponsorship -- is trying to reach out to elements in the Taliban command who it is though might be ready to talk peace.

The implication of today's bomb attack is that others in the Taliban do not want such talks to take place and will act accordingly.

Paul WoodBBC News, Kabul

Worried relatives clustered around the twisted metal which marked the entrance to the shopping centre - looking for family members inside. In fact, none of the shoppers, workers or hotel guests were hurt.

They were saved by the two security guards at the front door who fought a brief gun battle with the suicide attacker before he detonated himself or was exploded by bullets.

This is the second attack in Kabul in two weeks. The capital had been enjoying a year of relative calm. That now appears to have come to an end.

There are various theories as to why. One is that the Taliban-affiliated group blamed for most attacks in Kabul - the Haqqani network - had been observing a unilateral ceasefire, but is no longer doing so. Another theory - from intelligence sources - is that there is a new Taliban splinter group which is seeking to make its mark.source