A Syrian refugee woman reacts as she and family members jump off a overcrowded dinghy after landing safely on the Greek island of Lesbos after crossing a part of the Aegean Sea from the Turkish coast (seen in the background), September 19, 2015. REUTERS/Yannis Behrakis

Volunteers provide medical help to a pregnant Syrian refugee woman shortly after she arrive on a overcrowded dinghy at a beach on the Greek island of Lesbos after crossing a part of the Aegean Sea from the Turkish coast, September 19, 2015.REUTERS/Yannis Behrakis

Volunteers provide medical help to a pregnant Syrian refugee woman shortly after she arrive with her family on a overcrowded dinghy at a beach on the Greek island of Lesbos after crossing a part of the Aegean Sea from the Turkish coast, September 19, 2015. REUTERS/Yannis Behrakis

A Syrian refugee carries his child at a beach on the Greek island of Lesbos after crossing part of the Aegean Sea from the Turkish coast, September 19, 2015. REUTERS/Yannis Behrakis

A woman reacts as she arrives aboard a dinghy after crossing from Turkey, to the island of Lesbos, Greece, on Saturday, Sept. 19, 2015. (AP Photo/Petros Giannakouris)

A Syrian woman reacts as she arrives aboard a dinghy after crossing from Turkey, to the island of Lesbos, Greece, on Saturday, Sept. 19, 2015. (AP Photo/Petros Giannakouris)

A Syrian woman holds her child after they arrive aboard a dinghy from Turkey, to the island of Lesbos, Greece, on Saturday, Sept. 19, 2015. (AP Photo/Petros Giannakouris)

Syrian refugees arrive aboard a dinghy after crossing from Turkey, to the island of Lesbos, Greece, on Saturday, Sept. 19, 2015. (AP Photo/Petros Giannakouris)

Lifevests that have been used by migrants crossing from Turkey to Greece are seen on the beach of the island of Lesbos, Saturday, Sept. 19, 2015. (AP Photo/Petros Giannakouris)

A Syrian woman covered with a thermal blanket stands with her children after they arrive with others from Turkey, to the island of Lesbos, Greece, on Saturday, Sept. 19, 2015. (AP Photo/Petros Giannakouris)

A woman reacts as she arrives aboard a dinghy after crossing from Turkey, to the island of Lesbos, Greece, on Saturday, Sept. 19, 2015. (AP Photo/Petros Giannakouris)

Ihab, 30 (C), a Syrian migrant from Deir al-Zor, cries as he and his family are welcomed by his relatives upon their arrival at the railway station in Lubeck, Germany September 18, 2015.EUROPE-MIGRANTS/JOURNEY REUTERS/Zohra Bensemra/Files

Yasmine, 6, a Syrian migrant from the Syrian city of Deir al-Zor, is fed by her grandmother as her father Ihab looks on, during a welcoming dinner at her house upon their arrival in Lubeck, Germany September 18, 2015. EUROPE-MIGRANTS/JOURNEY REUTERS/Zohra Bensemra/Files

Ihab, 30, a Syrian migrant from Deir al-Zor, takes photographs from a train as he travels with his family from Hamburg to Lubeck, Germany, where his parent have taken refuge, September 18, 2015 file picture. REUTERS/Zohra Bensemra/Files

Abeer, 26, a Syrian migrant from Deir al-Zor, uses her mobile phone while her daughters Yasmine, 6 (R), and Hanine, 3, jokes with their father Ihab as they travel from Hamburg to Lubeck, Germany, in this September 18, 2015 file picture.EREUTERS/Zohra Bensemra/Files

Ihab, 30 (R), a Syrian migrant from Deir al-Zor, sleeps beside his daughter Yasmine, 6, inside a train as they head to meet his parents in Lubeck, Germany, in this September 18, 2015 file picture. REUTERS/Zohra Bensemra/Files

Ihab, 30, a Syrian migrant and his family (L) from the Syrian city of Deir al-Zor, attend a welcoming dinner by his parents at their house upon their arrival in Lubeck, Germany, in this September 18, 2015 file picture. REUTERS/Zohra Bensemra/Files

Police in Germany said on Sunday there had been an arson attack on a planned accommodation centre for migrants in the southwestern state of Baden-Wuerttemberg, the latest sign of tension as migrants flow to the country.

Police in the city of Heilbronn said no-one had been in the sports hall in nearby Wertheim at the time of the attack and it was not possible to enter the building because of fire damage.

The attack came as a senior member of parliament in Chancellor Angela Merkel's conservative sister party, the Christian Social Union (CSU), spoke out in favour of tighter rules on granting asylum.

"Those who are not in danger should leave Germany as quickly as possible," Gerda Hasselfeldt told the Welt newspaper.

"We have to set clear priorities. We need our energy and resources for those who are fleeing war and persecution."

The comments came as Hungary and Croatia traded threats as thousands of migrants poured over their borders, deepening the disarray in Europe over how to handle the crisis.

A proposal being argued over ahead of a meeting of European Union interior ministers on Tuesday would, if agreed, relocate 120,000 asylum seekers over the next two years around the whole bloc.

The number of migrants entering Germany, which recently reimposed border controls, was lower on Saturday, with 1,710 people registered, than on Friday, when the number was 1,985, police said.

Online Editors