Armenian lawmakers have approved a constitutional reform that would trim presidential powers and give more authority to parliament and the prime minister.

The parliament voted Monday 104-10 with three abstensions to put the reform to a popular vote, which is to be held before the end of the year. Under the proposed changes, the president will have largely symbolic powers and will be elected by parliament instead of a public vote as now.

The opposition has seen the reform as an attempt by President Serge Sarkisian to extend his rule. Sarkisian has denied the claims, saying he has no intention of shifting into the premier's seat after his current second term ends in 2018.

Several hundred opposition supporters rallied outside the parliament Monday, and police briefly detained 21 of them.