KABUL, Afghanistan — Eleven Taliban commanders have been released from a high-security prison in Afghanistan, according to Taliban officials, in an apparent deal that included a prominent regional leader caught five years ago personally escorting a shipment of nearly a ton of opium.

Afghan and American officials have remained silent about the releases from the prison, near the Bagram Air Base outside Kabul. A senior Afghan official said the 11 Taliban prisoners had been released in return for three Indian engineers after months of negotiations with local Taliban commanders in northern Baghlan province, where the engineers were kidnapped last year. The Indian Embassy in Afghanistan declined to comment.

The releases, which took place on Sunday, came just days after Zalmay Khalilzad, the United States diplomat and chief negotiator with the Taliban, went to Islamabad, Pakistan, and met with Taliban representatives. It was Mr. Khalilzad’s first meeting with them since President Trump called off negotiations with the insurgents on the eve of a potential breakthrough.

The potential release of thousands of Taliban prisoners was part of those negotiations. But that issue was a main point of contention with Afghan officials who were furious that their government was excluded from those talks, and that the United States was negotiating the release of prisoners being held under Afghan authority.