YEREVAN (AFP) -- Armenian ex-president Levon Ter-Petrosian told thousands of supporters Friday he would run in February's presidential poll, signaling the first serious challenge to the current leadership in a decade.

""I declare myself a candidate in the next presidential election,"" Ter-Petrosian told a crowd of up to 15,000 supporters in the capital Yerevan.
If successful, his return to office could signal a major shift in Armenia's fraught relations with neighbors Azerbaijan and Turkey.
Ter-Petrosian, 62, is an advocate of compromise with the two countries, which have closed their borders and imposed economic embargoes over Armenia's support for the breakaway Azerbaijani region of Nagorny Karabakh.
Relations are also tense with Turkey over the mass killings of ethnic Armenians that took place in the Ottoman Empire during World War I.
During a 90-minute speech frequently interrupted by applause and the chanting of his name, Ter-Petrosian lambasted the current leadership as ""corrupt from top to bottom"" and a ""mafia-style, criminal regime.""
Armenia needed to end its regional isolation by normalizing relations with Azerbaijan and Turkey, he said.
""Until we have resolved the questions of the blockade of Armenia, relations with our neighbors and Karabakh, Armenia cannot develop and strengthen,"" he said.
""As a result of the criminal policies of the current government, Azerbaijan has only toughened its position and will not seek compromise,"" he added.
Analysts say Ter-Petrosian is perhaps the only Armenian politician with the clout and experience to mount a challenge to the current leadership.
Earlier Friday, President Robert Kocharian said that if the ex-president joined the race he would remind Armenians of the severe economic hardships suffered under the rule of Ter-Petrosian and his Armenian National Movement (ANM).
""They fondly think that people have forgotten the rule of the ANM, but we will remind those who have forgotten,"" Kocharian said.
""The ANM left a very bad legacy of economic chaos. ... Our people do not want a return to the 1990s.""
Friday's rally marked the culmination of recent efforts by Ter-Petrosian's supporters to prepare for a dramatic political comeback. Ter-Petrosian has spent recent weeks meeting with voters and Armenia's opposition to gauge support for his return to politics.
Ter-Petrosian led Armenia from its independence from the Soviet Union in 1991, to 1998, when he was forced to resign by key members of his cabinet, including then prime minister Kocharian.