Zimbabwe ? Just three weeks before Zimbabwe’s presidential runoff, Robert Mugabe is giving the opposition little room to campaign – detaining its candidate, banning rallies and attacking diplomats who try to investigate political violence.

Even food is being used as a weapon, American and British officials said, with a ban on aid agencies ensuring that the poorest Zimbabweans must turn to Mugabe for help even if they blame him for the collapse of the economy. The government denied the allegations.

Opposition leader Morgan Tsvangirai out-polled Mugabe and two other candidates in the first round of voting March 29, but did not get the simple majority necessary to avoid a runoff. In recent days, it has become increasingly clear that Mugabe does not plan to let Tsvangirai come close to toppling him in the June 27 runoff.

Tsvangirai tried to campaign around Bulawayo, Zimbabwe’s second-largest city, on Friday, but he was stopped at two roadblocks. At the second, he was ordered to go to a police station about 30 miles from Bulawayo.