KABUL, April 30 (Xinhua) -- At least 23 people, including two assailants, were killed and 27 others wounded after two suicide bomb blasts rocked a diplomatic district in central Kabul on Monday morning, officials said.

The latest figures showed that 21 people were killed in Monday morning's two explosions and 27 others wounded, Waheed Majroh, a public health ministry spokesman, tweeted.

Two assailants also died on the spot.

A suicide bomber riding a motorcycle detonated his explosive roughly at 08:00 a.m. local time in Shash Darak locality in Police District 9 of the city, according to Kabul police.

The second blast occurred around 40 minutes later after rescue teams, responding police and reporters gathered at the site.

Those among the killed were three Afghan journalists, including an Afghan photo journalist of AFP news agency, according to an Afghan journalist advocacy agency.

The target of the blasts has yet to be determined, but the explosions occurred near a sub-office of National Directorate of Security (NDS), the country's primary intelligence agency.

Sirens could be heard after the blast in the fortified area where several foreign embassies, the NATO-led coalition forces' headquarters, and scores of apartment buildings are located.

No group has claimed responsibility for the attacks yet.