YANGON, Myanmar (AP) - Myanmar's reformist president granted a pardon Monday to people convicted of or charged with a variety of political offenses, an apparent effort to fulfill his pledge to free all political prisoners by the end of this year.

   It wasn't immediately clear how many people are covered by President Thein Sein's pardon, which was announced on state television.

   The pardon covers people convicted of or charged with unlawful association, high treason, contempt of government and violation of the peaceful assembly law.

   In addition to freeing those convicted of such crimes, the decree halted all ongoing trials and investigations on those charges.

   ``There are about 40 remaining political prisoners and 200 activists who are facing trial under political charges,  but it is difficult to guess how many will enjoy the pardon this time,'' said Ye Aung, a former political prisoner and member of the government's political prisoner scrutinizing committee.

   Technically, the pardon may not cover all prisoners the committee lists as political detainees because some were convicted of other crimes, such as murder and desertion.

   Ye Aung said only when it is learned who has actually been freed will it be clear whether all political prisoners were covered.

   Since Thein Sein became president, he has freed about 1,300 political prisoners, Ye Aung said.

   Thein Sein, a former general who became an elected president in 2011 after five decades of repressive military rule, instituted political and financial reforms to lift the country's sagging economy. It had faced sanctions from Western nations _ most now lifted _ because of its poor human rights record and undemocratic rule.

   The release of political detainees is a benchmark used by Western nations to judge Thein Sein's administration. Previous releases have been a major factor in decisions by those nations to ease sanctions.

   ``The president is implementing his promise to free all political prisoners and we welcome the announcement,'' said Ye Aung, who had been imprisoned under the previous military junta for eight years.  ``The government does not use the word prisoners of conscience in its announcement but all the laws mentioned in the announcement are those that are used against activists and dissidents.''

   Ye Aung said that during Thein Sein's administration, many activists had been charged under a section of the Peaceful Assembly Law that carries a maximum one-year prison term for those who stage protests without official permission, and for disturbing public tranquility, which carries a maximum two-year jail term.