World Bulletin / News Desk 

A powerful explosion ripped through central Kabul during morning rush hour Tuesday, a week after the Taliban announced the start of their annual spring offensive. A number of people have been killed, according to the Afghan presidential office.

The blast struck a densely packed neighbourhood close to several military compounds, according to police sources.

There was no immediate word on the extent of the casualties. However the Afghan presidential office said "a number of people" were killed and wounded.

The blast rattled windows several miles away and sent a plume of thick smoke rising in the sky.

Police sources told reporters the blast occurred near the NDS (National Directorate of Security) compound in central Kabul, which is near the Ministry of Interior headquarters.

Warning sirens blared out from the embassy compound, which is also close to the headquarters of the main NATO-led mission in Afghanistan. There was no indication of the source of the blast, but rocket attacks remain relatively common in the city.

The US embassy said they were not affected by the blast. The NATO military coalition also said they were unaffected.

The Afghan Taliban last Tuesday announced the start of their "spring offensive" even as the government in Kabul seeks to bring the insurgents back to the negotiating table to end their drawn-out conflict.

The Taliban warned they would "employ large-scale attacks on enemy positions across the country" during the offensive dubbed Operation Omari in honour of the movement's late founder Mullah Omar, whose death was announced last year.

The annual spring offensive normally marks the start of the "fighting season", though this winter the lull was shorter and they continued to battle government forces albeit with less intensity.