Scores of refugees and migrants are feared drowned after the boats they were travelling in capsized off Libya’s coast in the Mediterranean Sea, according to aid agencies and officials.

Ayoub Qasim, a spokesman for Libya’s coastguard, told The Associated Press news agency that two boats carrying around 300 people sank around 120km east of the capital, Tripoli, before adding that 134 others were rescued.

However, the International Organization for Migration (IOM) said in a Twitter post on Thursday that more than 150 people were feared drowned while 145 were rescued and returned to Libya after the incident.

Charlie Yaxley, spokesman for the United Nations refugee agency (UNHCR), said the survivors were picked up by local fishermen and then taken back to shore by the Libyan coastguard. “We estimate that 150 migrants are potentially missing and died at sea,” he said. “The dead include women and children.” “The worst Mediterranean tragedy of this year has just occurred,” Filippo Grandi, the United Nations high commissioner for refugees, said.

He called on European nations to resume rescue missions in the Mediterranean, halted after a European Union decision, and appealed for an end to migrant detentions in Libya. Safe pathways out of the North African country are needed “before it is too late for many more desperate people”, Grandi said.

Qasim told AFP news agency that most of the rescued from the sea were from Ethiopia while others were Palestinians and Sudanese.

Sabah Youssef, from Sudan, lost her seven-year-old child after the boat sank. “I don’t want anything now except to go back to my country, Sudan, to die there,” Youssef, who was rescued, told Reuters news agency.

Some of the survivors shared their ordeal at the sea. “In the afternoon, we started from Libya going to Italy, but when we went there, after one hour the ship started to sink and most of them (people) sank,” an unnamed survivor from Eritrea told AP.

Another survivor from Eritrea added: “We rescued ourselves. No-one could help us and no one came to rescue us, and here we are in a big problem so we need you