An Afghan official says a possible suicide bomber carried out an attack in Kabul, the capital. The Taliban has claimed responsibility.

Sediq Sediqqi, spokesman for the Afghan Interior Ministry, said Tuesday that the suicide attack was followed by gunfire, and the area has been surrounded by security forces.

There are fears of casualties, but there is no report on that yet, he added.

The target of the attack is not known, but the Ministry of Defense and one of the country's intelligence service's offices are near the blast site.

Taliban spokesman Zabihullah Mujahid says the militant group claimed responsibility for the attack.

Taliban insurgents have stepped up their attacks against the security forces since announcing the start of their spring offensive last week.