Nairobi: Sudan on Tuesday continued with its aerial bombardment of South Sudan, dropping eight bombs overnight, an official said, as South Sudan's president said the attacks amounted to a declaration of war by Sudan.

South Sudan's military spokesman Col Philip Aguer said that Sudanese Antonovs dropped eight bombs overnight between 11 pm and 1 am in Panakuac, where he said ground fighting had been ongoing since Sunday.

Aguer said he has not received information on whether there were casualties from the attack because of poor communications.

on Monday, Sudanese warplanes bombed a market and an oil field in South Sudan, killing at least two people after Sudanese ground forces had reportedly crossed into South Sudan with tanks and artillery.

South Sudan seceded from Sudan last year as a result of a 2005 peace treaty that ended decades of war that killed 2 million people. The countries have been fighting over the sharing of oil revenues and a disputed border.

South Sudan's President Salva Kiir on Tuesday during a visit to Beijing told China's president that attacks by rival Sudan amount to a declaration of war on his country.

There has yet to be a formal declaration of war by either of the Sudans, and Kiir's remark, made during talks with President Hu Jintao, signals a ratcheting up of rhetoric between the rival nations which have been teetering on the brink of war.