"The government has asked the ICRC to close the Jaffna and Vavuniya offices and operate only from Colombo," she told AFP, adding that no reason had been given for the move.
Wijeratne said the Jaffna office provided artificial limbs to war victims while the office in Vavuniya helped families visiting detained relatives.
There was no immediate confirmation from the government, but Sri Lankan authorities earlier this month tightened control over local and international non-governmental organisations.
The government information department said there were 250 international and 1,000 domestic aid agencies working in Sri Lanka, which would now have to register with the defence ministry following a change in the law.
Sri Lankan authorities have long been suspicious of aid agencies, which were often seen as sympathising with the Tamil Tigers during the country's civil war.The conflict ended when the rebels were wiped out in a military offensive that has since triggered allegations of war crimes.