South Sudan: president Salva Kiir says Khartoum ‘declared war’

South Sudan's president, Salva Kiir, said in Beijing Tuesday that Sudan's president had "declared war" on his country, according to the BBC.

On Monday, Sudan's air force bombed Bentiu, a border town, killing two and wounding ten. The United Nations urged both sides to "cease all hostilities immediately," the Washington Post reported. A South Sudanese military intelligence officer also said the attack "amounts to a declaration of war."

"The attack Monday came hours after Sudanese forces launched an incursion more than six miles inside South Sudan’s border — and three days after South Sudan ordered a withdrawal of its troops from the contested oil town of Heglig to give international diplomacy a chance to solve the disagreements between the nations," the Post wrote. Khartoum denied the attack, but witnesses and experts believe Sudan was behind the attack.

The Associated Press noted that despite Kiir's statement, there is so far no "formal declaration of war" by either of the two countries. Kiir is in China to push for diplomatic and economic support. 

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The two countries have been fighting since South Sudan became independent last year. Their border is not fully demarcated, and oil-rich areas are disputed.

Omar al-Bashir, Sudan's president, is a fiery orator and likes to brandish a stick when speaking, according to Reuters. In recent speeches he called the Sudan People's Liberation Movement "insects" and promised to "liberate" Sudan's southern neighbor.