Opposition leader Benazir Bhutto, who is demanding the ouster of President Mohammed Zia ul-Haq, brought her campaign to Zia's center of power today.

In what seemed the clearest demonstration so far that both sides are trying to avoid a violent confrontation, Bhutto addressed a noisy but peaceful demonstration here, only a few miles from Zia's home and the headquarters of the Army that kept him in power for 8 1/2 years of military rule. Both the government and Bhutto's Pakistan People's Party provided heavy security as up to 60,000 Pakistanis cheered her call for Zia to resign and allow new elections.

In her speech, Bhutto emphasized the symbolic political importance of Rawalpindi, where she once lived in the prime minister's official residence while her father, Zulfiqar Ali Bhutto, was in power. Zia overthrew Bhutto in 1977 and allowed him to be hanged in the Rawalpindi city jail after a disputed murder conspiracy conviction.

As she has almost daily since returning from exile last week, Bhutto declared that Zia has "neither a moral nor a legal right" to rule. Zia this week said Bhutto's rallies had "generated more heat than light," and warned that the authorities would crack down if the demonstrations turned violent.

In her speech, Bhutto appeared to characterize Zia's warning as a threat to return the country to martial law, which he lifted last December for the first time since taking power. Such a move, she said, would be impossible.

Despite the angry rhetoric, both sides were careful today to prevent the emotional crowd from approaching political landmarks such as the jail, the Army headquarters, or Zia's home at the official residence of the Army chief of staff -- a position he still holds.

Today's rally was notable for its lack of anti-American sentiment. One large banner atop Bhutto's stage declared, in Urdu, "Long live socialism; death to American imperialism."

But, only two days after Pakistani leftists and Moslem fundamentalists had attacked American institutions in Lahore over the U.S. air raids against Libya, today's demonstration avoided an overt anti-U.S. theme. Both the British and American embassies in neighboring Islamabad had warned their citizens to keep out of Rawalpindi during today's rally, but fears of attacks on Americans did not materialize.

Bhutto, who received support for her return earlier this spring from some Democratic politicians in Washington, has sought to downplay the anti-American feelings of some of her more militant supporters.