ANKARA, Turkey (AP) — Ruling in a politically divisive case, a Turkish appeals court on Wednesday upheld the convictions of 237 military officers for plotting to overthrow the Islamic-based government in 2003.

The Ankara-based court, however, overturned the convictions of 88 others, citing a lack of evidence or incorrect charges and opening the way for a possible new trial. The appeals court also upheld the lower court's decision to acquit 33 suspects.

The military officers were convicted last year and sentenced to up to 20-year jail terms in the case that has been touted as marking an end to the Turkish military's hold on politics. But the case has been marred by alleged judicial flaws and allegations of fabricated evidence.

Critics see the prosecutions as a government attempt to intimidate government opponents while others regard it as a step strengthening democracy in the country.

The case against the officers was filed in 2010 after Turkey's Taraf newspaper published what it said were leaked copies of documents by conspirators detailing their plans. They included blowing up mosques during Friday prayers, assassinating some religious minority leaders and shooting down a Turkish warplane and blaming it on Greece. It was claimed the conspirators hoped the chaos would lead to a military takeover.

Critics claimed the case was built on fabricated evidence.

"This is a sad decision. It is sad not only for the families of the officers and the defendants, but for the whole of Turkey," defense lawyer Celal Ulgen told private NTV television. "Such a decision was handed down despite illegal evidence."

Ulgen said the high court's decision on the 237 defendants would now be appealed at either Turkey's supreme court or at the European Court of Human Rights.

There was no immediate comment on the appeals court decision from Prime Minister Recep Tayyip Erdogan's government. The government has in the past hailed the trial, which began in December 2010, as a move toward greater democracy.

Defendants whose convictions and sentences were confirmed include former air force chief Ibrahim Firtina, former navy chief Ozden Ornek, former army commander Cetin Dogan, and Engin Alan, a former general elected to Parliament two years ago. The top officials were accused of being among the masterminds of the plot.

The trial of the high-ranking officers — inconceivable in Turkey a decade ago — has helped significantly to tip the balance of power in the country in favor of civilian authorities.

Turkey's generals have staged three coups since the 1960s and forced an Islamist government to quit in 1997.

But Erdogan's government has grown more confident with each of its three electoral successes since 2002, and has been limiting the powers of the armed forces.