The New Nation - Internet Edition

AFP, Ndjamena

Chad closed its border with Sudan on Monday, its government said, ramping up tensions between the volatile neighbours after Khartoum accused Ndjamena of backing a rebel assault on the Sudanese capital.

The Chadian government ordered the "airtight sealing of the frontier in order to avoid all infiltration and suspect traffic" across its porous eastern border, and froze economic and cultural ties, a government statement said. The move aims "to ensure the security of its territory and citizens and protect its economic and cultural interests" and to "guard against all surprises," said the statement, issued after a meeting of Chad's ministers.

The border between Chad's volatile east and the stricken region of Darfur was crossed earlier this year by rebels as they launched an armed coup attempt -- the second in as many years -- against Chadian President Idriss Deby Itno.

Deby accused Sudan of backing the fighters whom his forces drove back in intense fighting when they stormed the Chadian capital in February.

Relations have been tense between the two countries since 2003 when war broke out in Darfur, sending hundreds of thousands of desperate refugees fleeing across the Chadian border.