A bomb exploded today in an elevator shaft in a Cape Town building that houses the controversial President's Council, which last month recommended constitutional reforms in South Africa's strict apartheid system. Police reported one unidentified white man was killed by the blast.

The attack was the latest in a surge of sabotage incidents this week after a six-month lull. Many of the recent attacks have been blamed on the African National Congress, a black political organization that was banned in 1960 and has turned increasingly to violence in its campaign against the white-minority government. Top defense officials have been saying a resumption of congress activity was imminent.

Six explosions Wednesday night destroyed sections of the railroad leading to South Africa's main coal-exporting port of Richard's Bay, north of Durban. Two other explosions in the same area, near the small Natal town of Paulpietersburg, set a major fuel depot ablaze.

Thursday night explosions wrecked overhead power lines on the railroad between Johannesburg and the black suburb of Soweto.

The President's Council is a political body established by the government last year to pave the way for political reform. It presented proposals for constitutional reform May 12, which are due to be considered by the ruling National Party's representatives at a meeting in Cape Town Saturday.

The council is made up of government-nominated white, Colored (people of mixed race) and Asian members. Its proposals advocate the extension of parliamentary representation to Coloreds and Asians but not to the black majority.