BEIJING: A blast at a Chinese tax office killed four people and injured 19 more on Friday, in what police believe was a deliberate attack, state media reported.

Xinhua news agency, citing a police statement, said the explosion hit a regional tax office in the central province of Hunan.

The report said police investigations showed the blast was "a planned attack", but gave no further details or possible motive.

BDST:0933 HRS, July 31, 2010