The relocation of 15,000 refugees living since February in makeshift tent cities at the Greek Idomeni border crossing with the Former Yugoslav Republic of Macedonia (FYROM) and Piraeus port is a top priority for Greece, government spokeswoman Olga Gerovassilis said on Tuesday.

Meanwhile, tensions are building at other reception facilities, such as the site of the former Athens airport Hellenikon, local authorities warned, stressing that managing the refugee crisis was a growing challenge for the country.

The government has accelerated efforts to set up more organized accommodation centers and transfer the people still staying in the open, Gerovassilis said during a regular press briefing in Athens, as hundreds of refugees were bused from Piraeus to the newly established Skaramangas camp nearby.

About 1,000 refugees and migrants have been transferred since Monday, she said, stressing the evacuation operation should be finished by May 1.

The same stands for Idomeni where tensions remained high on Tuesday after Sunday's clashes between FYROM forces and some 700 refugees who tried to tear down the fence which resulted in more than 300 injuries by rubber bullets.

"Do not listen to rumors that the borders will reopen," the Greek official said, as Greek police announced that 15 activists -- 13 from European countries and two Greeks -- were detained for encouraging refugees to forcibly cross into the FYROM.

Border police on both sides of the fence were on alert also on Tuesday amidst rumors that unidentified groups of people were telling refugees they would provide them with petrol bombs this time, Greek national news agency AMNA reported.

About 11,200 people remain in the area hoping in vain they may soon be allowed to continue their journey to central Europe, while a further 3,800 remain camped at Piraeus port, according to the latest official statistics released on Tuesday by the government.

Some 53,000 refugees and migrants have been trapped across Greece since mid-February, when Austria and Balkan countries closed their borders after more than one million had reached the Aegean Sea islands via Turkey since early 2015.

Despite the distribution of leaflets in Arabic by Greek authorities this week informing refugees on the aid they would receive at organized camps, several appear reluctant to be transferred.

At the same time, there were warnings about tension rising because of congestion in some facilities, such as the Hellenikon camp.

"We are afraid a tragedy may occur sooner or later," Mayor of Argyroupolis-Hellenikon municipality Yannis Konstantatos told local MEGA TV on Tuesday.

The camp was initially created to accommodate some 800 refugees for a few weeks, but grew into an overcrowded facility housing 6,000 people.

Scuffles among refugees over food or mobile chargers are more and more frequent and local residents have expressed concerns about possible public health risks as the living conditions are problematic. There are only 30 to 40 toilets for 6,000 people, Konstantatos noted.

Source: XINHUA