21.   US-Saudi relations have been tense since the attacks, in which several of the hijackers were Saudi nationals.

22.   US-Cuban relations have grown more tense since the February downing of the Brothers to the Rescue planes.

23.   West Kalimantan has been tense since early January following clashes between thousands of indigenous Dayak tribesmen and migrants from Madura, an island off East Java.

24.   West Kalimantan province has been tense since early January following clashes between thousands of indigenous Dayak tribesmen and Moslem migrants from Madura, an island off East Java.

25.   Relations between the two Koreas have been tense since the rice talks collapsed with the South saying Pyongyang has moved military units including planes closer to the demilitarized zone.

26.   Relations have remained tense since then.

27.   Relations between Greece and Macedonia have been tense since February last year when Greece decreed an economic embargo against the former Yugoslav republic.

28.   Relations between Iran and Germany have been tense since November, when German prosecutors accused Iranian state leaders of approving the four murders which occurred in a Berlin restaurant.

29.   The border has remained tense since the death of North Korean president Kim Il-Sung last July, which ruptured inter-Korean dialogue.

30.   The political situation in Burundi has been tense since ethnic massacres last year in neighbouring Rwanda which has the same mix of majority Hutus and minority Tutsis.