it has cultivated various revenue streams, among which it switches as its military position or political circumstances change. External support During its early years, al-Shabaab received substantial external support in donations from the Somali diaspora or interested international jihadists, enabled by the weakness of the Somalian government's financial regulation framework and the ubiquitous use of the hawala system for receipt of remittances. Although al-Shabaab initially appeared a promising alternative to the Islamic Courts Union, its popularity with diaspora donors declined after the Ethiopian withdrawal and as the group gained a reputation for brutality. Concurrently, however, al-Shabaab increased its ties to other jihadist groups, especially al-Qaeda, which have extensive capacity to generate income in the Arabian Peninsula and Horn of Africa. For example, years before al-Shabaab became an official al-Qaeda affiliate, bin Laden publicly called on Muslims to send money to al-Shabaab. However, over the past decade, the counterterrorism efforts of foreign governments have obstructed international funding sources. According to authorities, the Somali state of Puntland is a key transit point for weapons shipments into Somalia from foreign countries – particularly frequent shipments of small arms and ammunition from Yemen, typically transported across the Gulf of Aden in skiffs, and occasionally larger shipments from the Makran coast of Iran. Puntland authorities have also seized Yemeni explosives shipments, which they suspect are the result of cooperation between al-Shabaab and Yemen-based AQAP. Alleged Eritrean support In December 2009, adopting Resolution 1907, the UN Security Council imposed sanctions on Eritrea, accusing the country of arming and financing militia groups, including al-Shabaab, in southern Somalia's conflict zones. Reports in 2010 and 2011 by a UN International Monitoring Group alleged continuing Eritrean support to Somali rebels – including, in the latter year, about $80,000 in monthly financial support and two air deliveries of weapons – but the Eritrean government emphatically denied the accusations, describing them as "concocted, baseless and unfounded". The International Crisis Group added some credence to Eritrea's denials, suggesting that historical Eritrean support to Somali miilitants had been aimed at undermining Ethiopia during its 2006–9 invasion, and that Hizbul Islam was more likely a recipient than al-Shabaab. On July 5, 2012, the U.S. government imposed sanctions on Eritrea's intelligence chief and a high-ranking military officer, who allegedly facilitated support to al-Shabaab. However, later that year, the UN Monitoring Group on Somalia and Eritrea reported that it had found no evidence of direct Eritrean support