tehran, aug 12 (afp) - the number of afghan refugees returning home from iran has reached 157,000 since april, picking up pace this month, a top interior ministry official said here monday.

"about 157,000 refugees have been repatriated to afghanistan" since a un project to help refugees return to the strife-torn country was launched in april, the director of iran's bureau for aliens and foreign immigrants, javad asadollahi told reporters.

so far this month, 20,000 refugees have returned, a faster pace than in previous months, asadollahi added.

asadollahi confirmed that the iranian government has extended a deadline for illegal afghan residents to leave iran until august 27.

previously, the date was fixed for august 11.

the news comes amid charges from the united nations refugee agency (unhcr) that iran is pressuring afghans to leave the islamic republic and locking up afghans in order to deport them.

unhcr officials expressed their concern to iranian authorities last month about the reported deportation of more than 16,000 afghans since march. last week, iran refused the unhcr access to screen afghan nationals in its jails.

since the fall of afghanistan's fundamentalist taliban regime in november 2001, the unhcr and iran have drafted a repatriation plan to facilitate the return of 400,000 refugees to afghanistan by 2003.

there are currently 2.3 million afghans living in iran, according to official figures.

the refugee issue will be on the agenda when iranian president mohammad khatami travels to kabul tuesday for talks with his afghan counterpart hamid karzai.